Protocol-A.texi 295 KB
Newer Older
David Byers's avatar
David Byers committed
1
\input texinfo                         @c -*-texinfo-*-
David Byers's avatar
David Byers committed
2 3
@c
@c FIXME: Explain how the garb works with nice and keep-commented
Per Cederqvist's avatar
Per Cederqvist committed
4
@c FIXME: Make all types clickable in HTML (and info?)
5 6 7 8
@c FIXME: Move history to appendices
@c FIXME: Move predefined aux-items to separate chapter
@c FIXME: Move misc-infos to chapter?
@c FIXME: Check for too much text before @menu.
9
@c FIXME: error-reply defined twice (conflicting).
10 11 12
@c FIXME: add link to Name Expansion from relevant reqs.
@c FIXME: Name Expansion collate table info is outdated.
@c FIXME: sentence-end-double-space!
David Byers's avatar
David Byers committed
13
@c
14
@c $Id: Protocol-A.texi,v 1.131 2001/05/01 16:41:03 ceder Exp $
David Byers's avatar
David Byers committed
15 16 17 18
@c %**start of header
@setfilename protocol-a.info
@settitle LysKOM Protocol A
@setchapternewpage odd
19 20 21 22 23
@c @afourpaper

@set PROTOEDITION 10.4
@set PROTOVER 10
@set VERSION 1.0.4
David Byers's avatar
David Byers committed
24

25 26 27


@c
28
@c Define a few strings that contains characters from ISO Latin-1.
29
@c
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

@iftex

@set IAM Inl@"a{}gg @}t mig
@set Pell P@"ar Emanuelsson
@set Kent Kent Eng@-str@"om@penalty-10000
@set presconf 27HPresentation (av nya) m@"oten

@end iftex
@ifnottex

@set IAM Inlägg @}t mig
@set Pell Pär Emanuelsson
@set Kent Kent Engström
@set presconf 27HPresentation (av nya) möten

@end ifnottex

48 49 50 51 52 53


@c
@c Index setup
@c

54 55 56 57 58 59 60
@c Index for asynchronous messages.
@defcodeindex am

@c Merge all indices.
@syncodeindex am fn
@syncodeindex tp fn

61 62 63 64 65 66


@c
@c Special markup for Protocol-A.texi
@c

67
@c @req{login} is used for protocol requests.
68

69 70 71 72
@macro req {n}
@code{\n\}
@end macro

73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115
@c @reqlink{login} is used for protocol requests, that shuld be linked.

@ifhtml
@macro reqlink {n}
@code{@ref{\n\}}
@end macro
@end ifhtml

@ifnothtml
@macro reqlink {n}
@code{\n\} (@pxref{\n\})
@end macro
@end ifnothtml

@c @reqdlink{login}...@linkhere{} is used for protocol requests, that
@c shuld be linked, where the link should occur a few words after the
@c request itself.

@ifhtml

@c HTML version: make the word a link.
@macro reqdlink {n}
@code{@ref{\n\}}@c
@unmacro linkhere
@macro linkhere
@end macro
@end macro

@end ifhtml

@ifnothtml
@ifnottex

@c Info version: create linkhere as a macro that contains a reference.

@macro reqdlink {n}
@code{\n\}@c
@unmacro linkhere
@macro linkhere
(@pxref{\n\})
@end macro
@end macro
@end ifnottex
116

117 118
@iftex

119
@c TeX version: this produces output similar to the Info version.
120

121 122 123 124 125 126
@tex
    \gdef\reqdlink#1{%
        \code{#1}%
        \gdef\linkhere{ (\pxref{#1})}%
    }
@end tex
127 128 129
@end iftex
@end ifnothtml

130 131 132 133 134 135 136 137 138 139
@c @aux{mx-allow-filter} is used for aux-item names.
@macro aux {n}
@code{\n\}
@end macro

@c @async{async-login} is used for async names.
@macro async {n}
@code{\n\}
@end macro

140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196
@c @asynclink{async-login} is used for async names, that shuld be linked.

@ifhtml
@macro asynclink {n}
@code{@ref{\n\}}
@end macro
@end ifhtml

@ifnothtml
@macro asynclink {n}
@code{\n\} (@pxref{\n\})
@end macro
@end ifnothtml

@c @asyncdlink{async-login}...@linkhere{} is used for async messages,
@c that shuld be linked, where the link should occur a few words after
@c the async name itself.

@ifhtml

@c HTML version: make the word a link.
@macro asyncdlink {n}
@code{@ref{\n\}}@c
@unmacro linkhere
@macro linkhere
@end macro
@end macro

@end ifhtml

@ifnothtml
@ifnottex

@c Info version: create linkhere as a macro that contains a reference.

@macro asyncdlink {n}
@code{\n\}@c
@unmacro linkhere
@macro linkhere
(@pxref{\n\})
@end macro
@end macro
@end ifnottex

@iftex

@c TeX version: this produces output similar to the Info version.

@tex
    \gdef\asyncdlink#1{%
        \code{#1}%
        \gdef\linkhere{ (\pxref{#1})}%
    }
@end tex
@end iftex
@end ifnothtml

197 198 199 200 201
@c @type{Conference} is used for LysKOM types.
@macro type {n}
@code{\n\}
@end macro

202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217
@c @lt{Conference} is used for linked types.  The link is only present
@c when it is unobtrusive.  It should only be used inside
@c @example...@end example.

@ifhtml
@macro lt {n}
@ref{\n\}@c
@end macro
@end ifhtml

@ifnothtml
@macro lt {n}
\n\@c
@end macro
@end ifnothtml

218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
@c @priv{wheel} is used for privilege bits.
@macro priv {n}
@code{\n\}
@end macro

@c @conftype{rd-prot} is used for conference type bits.
@macro conftype {n}
@code{\n\}
@end macro

@c @misc{bcc-recpt} is used for misc-info names.
@macro misc {n}
@code{\n\}
@end macro

@c @rarg{passwd} is used to reference arguments of requests.  This is
@c *only* used in the nodes that defines the requests.
@macro rarg {n}
@code{\n\}
@end macro

@c @aarg{text-no} is used to reference arguments of asynchronous
@c messages.  This is *only* used in the nodes that defines the
@c relevant asynchronous message.
@macro aarg {n}
@code{\n\}
@end macro

@c @errorcode{no-such-text} is used to mark error codes.
@macro errorcode {n}
@code{\n\}
@end macro

@c @field{ident-user} is used to mark fields of struct types.
@macro field {n}
@code{\n\}
@end macro

256 257 258 259 260 261 262
@c @reqexample is used immediately before Protocol-A example
@c fragments.
@macro reqexample
@need 2000
@i{Example:}
@end macro

263 264
@c %**end of header

David Byers's avatar
David Byers committed
265
@ifinfo
266 267 268
This is the LysKOM Protocol A specification, edition
@value{PROTOEDITION}.  It specifies version @value{PROTOVER} of the
protocol.  It corresponds to version @value{VERSION} of lyskomd.
David Byers's avatar
David Byers committed
269

Per Cederqvist's avatar
Per Cederqvist committed
270
Copyright @copyright{} 1995-2000 Lysator ACS.
David Byers's avatar
David Byers committed
271 272 273 274

Permission is granted to make and distribute verbatim copies of this
specification provided the copyright notice and this permission notice
are preserved on all copies.
275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290

@ignore
Permission is granted to process this file through TeX
and print the results, provided the printed document
carries a copying permission notice identical to this
one except for the removal of this paragraph (this
paragraph not being relevant to the printed manual).
@end ignore

Modified versions of this document may be redistributed with the added
condition that all modifications not cleared with the LysKOM development group
are clearly marked and that the entire modified work be redistributed under the
same conditions as the original.

Permission is granted to copy and distribute translations of this manual into
another language under the same conditions as for modified versions.
David Byers's avatar
David Byers committed
291 292
@end ifinfo

293 294 295 296
@c FIXME: What does this do?
@iftex
@parindent 0pt
@font@tensltt=cmsltt10
297
@tex
298 299 300 301 302
\global\def\rett#1{{\let\t\sltt\tt #1}}
\global\def\sltt#1{{\fam\ttfam\tensltt\let\t\rett #1}}
\global\let\t\sltt
@end tex
@end iftex
303

David Byers's avatar
David Byers committed
304 305
@titlepage
@title{LysKOM Protocol A}
306 307 308
@subtitle{Protocol version @value{PROTOVER}}
@subtitle{Edition @value{PROTOEDITION}}
@subtitle{(lyskomd @value{VERSION})}
David Byers's avatar
David Byers committed
309 310 311 312
@author by the LysKOM Developers

@page
@vskip 0pt plus 1filll
Per Cederqvist's avatar
Per Cederqvist committed
313
Copyright @copyright{} 1995-2000 Lysator ACS
David Byers's avatar
David Byers committed
314 315 316 317 318 319 320 321 322 323 324 325 326 327

Permission is granted to make and distribute verbatim copies of this document
provided the copyright notice and this permission notice are preserved on all
copies.

Modified versions of this document may be redistributed with the added
condition that all modifications not cleared with the LysKOM development group
are clearly marked and that the entire modified work be redistributed under the
same conditions as the original.

Permission is granted to copy and distribute translations of this manual into
another language under the same conditions as for modified versions.

@end titlepage
328 329 330
@ifnothtml
@contents
@end ifnothtml
David Byers's avatar
David Byers committed
331

332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349
@dircategory LysKOM
@direntry
* Protocol A: (protocol-a).             The LysKOM Protocol A specification.
@end direntry

@ifhtml
@html
<a href="http://www.lysator.liu.se/" ><img
src="http://www.lysator.liu.se/icons/lyslogo.gif" alt="Lysator"
width=40 border=0 height=40 align=left ></a>

<a href="http://www.lysator.liu.se/lyskom/" ><img
src="http://www.lysator.liu.se/icons/lyskom.gif" alt="LysKOM" width=40
border=0 height=40 align=left ></a>
<br clear=all>
@end html
@end ifhtml
@ifnottex
350
@node Top
351
@top LysKOM Protocol A
352

353 354 355 356 357 358 359
This document specifies version @value{PROTOVER} of LysKOM Protocol A.
This is edition @value{PROTOEDITION} of the specification.  It
corresponds to version @value{VERSION} of lyskomd.

The most up-to-date version if this document can always be found at 
@uref{http://www.lysator.liu.se/lyskom/protocol/}.
@end ifnottex
David Byers's avatar
David Byers committed
360 361

@menu
362 363 364 365 366 367
* Overview::                    
* Introduction::                
* Data Types::                  
* Protocol Requests::           
* Asynchronous Messages::       
* Error Codes::                 
368
* Name Expansion::              
369 370 371 372
* LysKOM Content Types::        
* The User Area::               
* Writing Clients::             
* Importing and Exporting E-Mail::  
373 374
* Protocol Version History::    
* Document Edition History::    
375
* Index::                       
David Byers's avatar
David Byers committed
376 377
@end menu

378
@node Overview
David Byers's avatar
David Byers committed
379 380
@chapter Overview

381 382 383 384 385
@iftex
This document specifies version @value{PROTOVER} of LysKOM Protocol A.
This is edition @value{PROTOEDITION} of the specification.  It
corresponds to version @value{VERSION} of lyskomd.

386 387
The most up-to-date version if this document can always be found on
the web at @uref{http://www.lysator.liu.se/lyskom/protocol/}.
388 389
@end iftex

David Byers's avatar
David Byers committed
390
LysKOM is a conferencing system@footnote{Or in modern terms, enabling
391 392 393 394 395 396
technology for Computer-Supported Cooperative Work (CSCW).}. Similar
systems were QZ-KOM and PortaCOM@footnote{Also known as ``PottaKOM'' and
``BortaKOM.''}. The LysKOM system is copyrighted by Lysator Academic
Computing Society and distributed under conditions of the GNU Public
License. LysKOM and its documentation is provided ``as is'' without
warranty of any kind.
David Byers's avatar
David Byers committed
397

398 399
Anything described here as ``unspecified'' is liable to change in
future protocol versions.
David Byers's avatar
David Byers committed
400 401

This specification is the work of several people. The main contributors have
402
been
David Byers's avatar
David Byers committed
403 404
Per Cederqvist @email{ceder@@lysator.liu.se}, 
David Byers @email{byers@@lysator.liu.se},
405
@value{Pell} @email{pell@@lysator.liu.se},
David Byers's avatar
David Byers committed
406 407 408
Thomas Bellman @email{bellman@@lysator.liu.se}, 
Lars Aronsson @email{aronsson@@lysator.liu.se},
Linus Tolke @email{linus@@lysator.liu.se} and
409
@value{Kent} @email{kent@@lysator.liu.se}.
David Byers's avatar
David Byers committed
410

David Byers's avatar
David Byers committed
411 412
The LysKOM developers can be reached by email to
@email{lyskom@@lysator.liu.se}.
David Byers's avatar
David Byers committed
413

414 415
@menu
* Notation::                    
David Byers's avatar
David Byers committed
416 417
@end menu

418
@node Notation
David Byers's avatar
David Byers committed
419 420
@section Notation

421
This specification uses a BNF-like grammar to describe the protocol and
422
its data elements.
David Byers's avatar
David Byers committed
423

424
Data fields have been given names that start with a lower-case letter.
425

426 427
Fundamental data types have names in all-caps (such as @type{INT32} and
@type{ARRAY}).
428 429 430

Derived data types have names that start with an upper-case letter. (If
the type contains more than one word, all words start with an upper-case
431
letter, like this: @type{Text-Stat}.)  The operator @code{::=} defines
432 433 434 435
the name to its left.

Comments start with @code{!} (exclamation mark) and alternatives are
separated by a @code{|} (vertical bar.) A @code{;} (semicolon)
436 437 438
terminates statements in the grammar. In some specifications there are
literal strings. There is to be no whitespace before or after literal
strings unless there is whitespace in the literal itself.
David Byers's avatar
David Byers committed
439 440


441
@node Introduction
David Byers's avatar
David Byers committed
442 443 444 445 446 447
@chapter Introduction

This chapter introduces the concepts used in LysKOM, such as articles,
conferences and sessions. 

@menu
448 449 450 451 452 453 454
* Articles::                    
* Conferences::                 
* The Misc-Info List::          
* The Aux-Item List::           
* Security::                    
* Membership and Reading::      
* Client-Server Dialog::        
David Byers's avatar
David Byers committed
455 456 457
@end menu


458
@node Articles
David Byers's avatar
David Byers committed
459 460
@section Articles

461
An article is represented as a value of the type @type{Text-Stat} and a
David Byers's avatar
David Byers committed
462
string containing the article contents. An article will usually have one
463 464
or more recipients and may be a comment or footnote to other articles.
Each article is kept in the database until it is older than the
465
@field{nice} value of each of its recipients and it is not marked by any
466
user.
David Byers's avatar
David Byers committed
467

468 469 470 471 472
Currently there is an array of @type{Misc-Info} included in the
@type{Text-Stat}. This array contains information about recipients,
senders, comments and footnotes. In the future the information
contained in the @type{Misc-Info} array will be integrated into the
@type{Text-Stat}.
David Byers's avatar
David Byers committed
473 474 475

Every article has at least one number, the global article number. Global
numbers are assigned in ascending order to new articles, and are never
476
reused. If an article has recipients it will also have a local number
Per Cederqvist's avatar
Per Cederqvist committed
477
for each recipient. Local numbers are used in some data structures to
478
provide more compact storage and to provide an ordering of articles for
479 480 481
a particular recipient. Local numbers are assigned in ascending order
and are never reused for a particular recipient, though different
recipients will have articles with the same local numbers.
David Byers's avatar
David Byers committed
482

483
Occasionally it is necessary to map between local and global numbers.
484
The server call @reqlink{local-to-global} does this.
David Byers's avatar
David Byers committed
485 486 487



488
@node Conferences
David Byers's avatar
David Byers committed
489 490
@section Conferences

491
Conferences hold articles. They are represented in the protocol as a
492 493 494
data type called @type{Conference}. Each conference has a
@dfn{creator}, the person who created the conference, and a
@dfn{supervisor}, a conference whose members can modify the conference.
David Byers's avatar
David Byers committed
495
If the supervisor is a person, the members of that person's mailbox
496
are supervisors, which in most cases is only that person. We have also
497
introduced a type called @type{UConference} (pronounced micro-conf-stat)
498
which holds a subset of the information contained in the full
499
@type{Conference} type. Use the @type{UConference} type whenever
500
possible since it places a much smaller load on the LysKOM server.
David Byers's avatar
David Byers committed
501

502 503 504 505
Each conference has a type, which is essentially a collection of
boolean flags. Currently the flags @conftype{rd-prot},
@conftype{letterbox}, @conftype{secret}, @conftype{original},
@conftype{allow-anonymous} and @conftype{forbid-secret} are defined.
David Byers's avatar
David Byers committed
506

507
@table @conftype
David Byers's avatar
David Byers committed
508 509 510 511 512
@item rd-prot
The conference is protected from reading by non-members. Persons become
members by having one of the existing members or supervisors add him or
her to the conference. This restriction is enforced by the server.
@item original
513 514 515 516
Conferences of this type are intended for original articles only.
Comments are to be redirected to the super-conference instead. This
restriction is currently not enforced by the server; clients must
implement this functionality.
David Byers's avatar
David Byers committed
517
@item letterbox
518
Conferences of this type are connected to persons. Letters to a person
David Byers's avatar
David Byers committed
519
are sent to the mailbox and the name of the mailbox is synchronized
520 521
with the person name. It is currently not possible to explicitly set or
clear this flag on a conference.
David Byers's avatar
David Byers committed
522 523
@item secret
Conferences of this type are secret. The server will not divulge any
524
information about the existence of the conference to persons who are not
David Byers's avatar
David Byers committed
525
members or supervisors of the conference. If a mailbox is made secret,
David Byers's avatar
David Byers committed
526 527
that person cannot log in using the person name, but must specify a
person number instead.
528 529 530
@item allow-anonymous
Conferences of this type accept anonymous articles. Other conferences
will reject anonymous articles.
David Byers's avatar
David Byers committed
531 532 533
@item forbid-secret
Conferences of this type do not allow secret members. If a conference is 
changed to this type, preexisting secret members remain secret.
David Byers's avatar
David Byers committed
534 535 536 537
@end table



538 539 540 541
@menu
* Persons and Sessions::        
@end menu

542
@node Persons and Sessions
David Byers's avatar
David Byers committed
543 544 545
@subsection Persons and Sessions

Persons are represented in the protocol by values of the type
546
@type{Person}. Associated with persons are statistics, a set of personal
547
flags and a set of privileges (@pxref{Security}). Persons are also
548
associated with a conference that has the same number as the person and
549
the @conftype{letterbox} bit set.
David Byers's avatar
David Byers committed
550 551

Connections to the server are represented as values of the type
552 553
@type{Static-Session-Info}, @type{Session-Info-Ident} or
@type{Session-Info}. Sessions have session number that are unique for
554 555 556 557
each session in the lifetime of the server execution. A single user can
have several sessions running at once. The session is not released until
the network connection is closed; a user can log in and out repeatedly
in a single session.
David Byers's avatar
David Byers committed
558 559


560
@node The Misc-Info List
David Byers's avatar
David Byers committed
561 562
@section The Misc-Info List

563
The @type{Misc-Info} list contains tagged data. The fields are sent in
564
groups pertaining to a particular type of information: information about
565 566
recipient; carbon copy recipient; blank carbon copy recipient;
comment to; footnote to; comment in
567 568 569
and footnote in. The information groups may be sent in any order and
there may be any number of groups. Within each group the elements are
always sent in the order listed below.
David Byers's avatar
David Byers committed
570

571
@subsection Recipient
David Byers's avatar
David Byers committed
572

573
@table @misc
David Byers's avatar
David Byers committed
574
@item recpt
575 576
Starts a recipient group. It contains the conference number of a
recipient of the article.
David Byers's avatar
David Byers committed
577
@item loc-no
578 579
Always present within a recipient group. It contains the local text
number of the article in the conference specified by the preceding
580
@misc{recpt} field.
David Byers's avatar
David Byers committed
581
@item rec-time
582 583 584
If the recipient is a person, this element is added by the server when
the recipient marks the article as read. It contains the time when the
text was read.
David Byers's avatar
David Byers committed
585
@item sent-by
586 587 588
Present when the recipient was added by a person other than the author
(after the article was created.) It contains the person number of the
person who added the recipient.
David Byers's avatar
David Byers committed
589
@item sent-at
590 591
Present when the recipient was added after the article was created. It
contains the time when the recipient was added.
David Byers's avatar
David Byers committed
592 593 594
@end table


595
@subsection Carbon Copy (CC) Recipient
David Byers's avatar
David Byers committed
596

597 598 599 600
The carbon-copy recipient group is identical to the recipient group
above. The difference is how new comments to an article with a recipient
or carbon-copy recipient are treated. A comment to an article is sent to
all recipients, but not to carbon-copy recipients of the original
Per Cederqvist's avatar
Per Cederqvist committed
601
article. This difference is enforced by the clients.
David Byers's avatar
David Byers committed
602

603
@table @misc
David Byers's avatar
David Byers committed
604
@item cc-recpt
605 606
Starts a carbon-copy recipient group. It contains the conference number
of a carbon-copy recipient of the article.
David Byers's avatar
David Byers committed
607
@item loc-no
608 609
Always present in a CC recipient group. It contains the local text
number of the article in the conference specified by the most recent
610
@misc{cc-recpt} field.
David Byers's avatar
David Byers committed
611
@item rec-time
612
Present after the CC recipient has read the article. It contains the
613 614
time when the article was read. Since only persons can read articles
this will only be seen if the CC recipient is a person.
David Byers's avatar
David Byers committed
615 616 617
@item sent-by
Present when a CC recipient was added by a person other than the author
after the article had been created. It contains the person number of the
618
person who added the CC recipient.
David Byers's avatar
David Byers committed
619 620 621 622 623 624
@item sent-at
Present when a CC recipient was added after the article had been
created. It is the time when the CC recipient was added.
@end table


625 626 627 628 629
@subsection Blank Carbon Copy (BCC) Recipient

The blank carbon-copy recipient group is identical to the carbon-copy
recipient group above. The difference is the visibility of the
information. A carbon-copy recipient group is visible to anyone that is
630
allowed to fetch both the text status of the involved text and the
631
conference status of the involved conference.  (That is, as long as the
632
conference isn't secret everybody is allowed to see the carbon-copy
633 634
recipient group.)

635 636 637 638 639
A BCC recipient group is basically only visible to members and
supervisors of the recipient.  Persons that have the right to become a
member of the recipient can also see it, as can the author of the text
(unless the recipient is secret to him).  This is enforced by the
server.
640 641

This type of group was introduced in protocol version 10.  When
642
old-style calls such as @reqlink{get-text-stat-old}
643 644
are used this will be converted to a CC recipient group by the server
for the benefit of clients that don't understand this group.
645

646
@table @misc
647 648 649 650 651 652
@item bcc-recpt
Starts a blank carbon-copy recipient group. It contains the conference
number of a blank carbon-copy recipient of the article.
@item loc-no
Always present in a BCC recipient group. It contains the local text
number of the article in the conference specified by the most recent
653
@misc{bcc-recpt} field.
654 655 656 657 658 659 660 661 662 663 664 665 666 667
@item rec-time
Present after the BCC recipient has read the article. It contains the
time when the article was read. Since only persons can read articles
this will only be seen if the BCC recipient is a person.
@item sent-by
Present when a BCC recipient was added by a person other than the author
after the article had been created. It contains the person number of the
person who added the BCC recipient.
@item sent-at
Present when a BCC recipient was added after the article had been
created. It is the time when the BCC recipient was added.
@end table


668
@subsection Comment To
David Byers's avatar
David Byers committed
669

670
@table @misc
David Byers's avatar
David Byers committed
671 672 673 674 675 676 677 678
@item comm-to
Always present when the article is a comment to another article.
@item sent-by
Present when the article was added as a comment by a person other than
the author, after the article had been created. It contains the person
number of the person who added the article as a comment.
@item sent-at
Present when the article was added as a comment after the article had
679
been created. It contains the time when it was added as a comment.
David Byers's avatar
David Byers committed
680 681 682
@end table


683
@subsection Footnote To
David Byers's avatar
David Byers committed
684

685
@table @misc
686
@item footn-to
David Byers's avatar
David Byers committed
687 688 689
Always present when the article is a footnote to another article.
@item sent-at
Present when the article was added as a footnote after the article had
690
been created. It contains the time when it was added as a footnote.
David Byers's avatar
David Byers committed
691 692 693
@end table


694
@subsection Comment in
David Byers's avatar
David Byers committed
695

696
@table @misc
David Byers's avatar
David Byers committed
697 698 699 700 701 702
@item comm-in
Present when there are comments to this article. It contains the article
number which is a comment to this article.
@end table


703
@subsection Footnote in
David Byers's avatar
David Byers committed
704

705
@table @misc
706
@item footn-in
David Byers's avatar
David Byers committed
707 708 709 710 711
Present when there are footnotes to this article. It contains the
article number which is a footnote to this article.
@end table


712
@node The Aux-Item List
713
@section The Aux-Item List
714 715 716 717 718

The aux-item list is used as a generic extension mechanism in the LysKOM
server and in protocol A. 

@menu
719 720 721 722 723
* About Aux-Items::             
* Predefined Aux-Item Types::   
* Client-Specific Aux-Item Types::  
* Experimental Aux-Item Types::  
* Defining New Aux-Item Types::  
724 725
@end menu

726
@node About Aux-Items
727
@subsection About Aux-Items
728 729 730 731

Aux-items were introduced in protocol version 10 as a mechanism for
extending the conference, text and server information structures without
changing the protocol. Persons were excluded since nobody could figure
David Byers's avatar
David Byers committed
732
out a case where setting an aux-item on the mailbox wasn't as good as
733 734 735
setting it on the person (another reason was that I was fed up writing
aux-item code by the time they were working on texts and conferences.)

736 737 738
The exact structure of an aux item is specified elsewhere
(@pxref{LysKOM Data Types}). The important fields here are the
@field{aux-no}, @field{tag} and @field{data} fields.
739

740 741 742 743 744 745
The @field{aux-no} field is used to identify an item. The
@field{aux-no} together with a text or conference number uniquely
identifies a particular aux item.  Items are numbered from one and up
within each item list. Once assigned, the @field{aux-no} for an item
is never changed. New items are guaranteed to be assigned numbers that
have never been used before within a particular list.
746

747 748 749 750
The @field{tag} field identifies the type of aux item. It is used by
the server and by clients to figure out how to interpret the data
field, and by the server to decide if the item needs special
treatment.
751

752 753 754 755
The @field{data} field is a simple string. The meaning of the string
is determined by the @field{tag} field, but since it is a string,
clients that have no understanding of the contents can successfully
parse the item anyway (in contrast to items in the misc-info list.)
756 757 758



759
@node Predefined Aux-Item Types
760
@subsection Predefined Aux-Item Types
761

David Byers's avatar
David Byers committed
762 763 764
Predefined Aux-Item types are part of Protocol A, and clients should
support all of them. As with other parts of the protocol, changes to
these definitions will be made backwards-compatible, if possible.
765

David Byers's avatar
David Byers committed
766 767 768
Creation and deletion of items with a predefined type can cause
arbitrarily complex and wonderous behavior in the server. Furthermore,
the server may place constraints on the items with regard to content,
769
flags, who can create them, to what objects they can be attached and
David Byers's avatar
David Byers committed
770 771
so forth. The server may also silently enforce specific values for any
field of an item, regardless of what the client requests.
772

773
All items with tags in the range 1-9999 and 30000 and up are considered
774 775
predefined. If a client attempts to create an item with a tag in this
range, but the server has no idea what that tag means, the server will
David Byers's avatar
David Byers committed
776
return an error (illegal-aux-item.)
777

778 779
Some of the aux-items below (mostly the ones that begin with "mx-") are
used by mail importers. For information about supplementary aux-items
780
introduced by @command{komimportmail}, see @ref{komimportmail Aux-Item Types}.
781 782 783

@table @samp
@item content-type [1] (text)
784
Specifies the content type of a text. Data is a valid MIME type or one
785
of the special LysKOM types (@pxref{LysKOM Content Types}).
786 787 788 789 790 791 792 793 794 795

This item may only be set by the author of a text. The inherit, secret
and hide-owner bits are cleared. Only one content-type item can be
created per creator.


@item fast-reply [2] (text)
Data is a string that constitutes a brief comment to the text. This
comment should be displayed immediately after the text body. 

David Byers's avatar
David Byers committed
796 797
An item of this type will never be inherited, can always be deleted, is
never anonymous and is never secret.
798 799


800
@item cross-reference [3] (text, conference, letterbox)
David Byers's avatar
David Byers committed
801
Data is a cross-reference to something else. The contents consist of a
802 803
letter, a number, and optionally a space and a descriptive text. The
letter must be one
David Byers's avatar
David Byers committed
804 805 806 807 808
of T, C or P. T specifies that the cross-reference points to a text; C
that it points to a conference; and P that it points to a person. The
number is the id of the target of the cross reference. The descriptive
text is simly that, a text that describes the cross-reference. For
example, "T15 Check this out!" is a cross reference to text 15 with a
809 810
description that reads "Check this out!", and "T17" is a cross reference
without a description.
811

David Byers's avatar
David Byers committed
812 813
The inherit bit is automatically cleared and the item can always be
deleted. 
814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846


@item no-comments [4] (text)
When this item is set, the author requests that nobody comments the
text. This is advisory only; it is still possible to write comments, but
clients should advise the user that this is contrary to the author's
wishes. Data should be empty.

This item may only be set by the author. The secret, hide-creator and
inherit bits are automatically cleared.


@item personal-comment [5] (text)
When this item is set, the author requests only personal comments. This
is advisory only; it is still possible to create regular comments, but
clients should advise the user that the author prefers a personal
comment. Data should be empty.

This item may only be set by the author. The secret, hide-creator and
inherit bits are automatically cleared.


@item request-confirmation [6] (text)
The author requests that everyone who reads the text confirms having
done so by creating read-confirmation items on the text. Clients should
ask users if they wish to confirm having read the text when it is
displayed. Data should be empty.

The hide-creator, secret and inherit bits are automatically cleared.


@item read-confirm [7] (text)
This item can be taken as confirmation that the item creator has read
847 848 849
the text to which the item is attached. Clients should never ever create
this item without an explicit confirmation from the user that the text
has indeed been read.
850 851

The hide-creator, secret and inherit bits are automatically cleared.
David Byers's avatar
David Byers committed
852
Once created an item of this type cannot be deleted.
853 854


855
@item redirect [8] (conference, letterbox)
David Byers's avatar
David Byers committed
856

David Byers's avatar
David Byers committed
857 858 859 860 861 862 863 864 865 866 867
This item indicates that texts should not be sent to the conference,
but be directed to some other target instead. Clients should notify
users that attempt to send texts to the conference of the redirect and
offer to send the text to the target of the redirect instead. A typical
use of this item would be a user that does not read LysKOM very often
and would like to advise other users to send e-mail instead.

Data is PROTOCOL:ADDRESS where PROTOCOL is either "E-mail" or "LysKOM",
and ADDRESS is either an e-mail address or a LysKOM conference. 
Hopefully we'll be able to replace this with a forwarding mechanism
later.
868 869

This item can only be set by the conference supervisor or in the case of
David Byers's avatar
David Byers committed
870
a mailbox, the person attached to the mailbox. The hide-creator and
871 872 873
secret bits are cleared automatically. Only one redirect can be
specified.

David Byers's avatar
David Byers committed
874

875
@item x-face [9] (conference, letterbox, server)
876 877 878 879

Data is the face of the person in compface format. Cool, innit?

This item can only be set by the conference supervisor or in the case of
David Byers's avatar
David Byers committed
880
a mailbox, the person attached to the mailbox. The hide-creator and
881 882 883
secret bits are cleared automatically. 


884
@item alternate-name [10] (text, conference, letterbox)
885 886

Data is a string that the client may use as an alternate to the name of
David Byers's avatar
David Byers committed
887 888 889
a conference or the subject of a text. Note that the server does not
match against this name when performing name lookups. Clients should
only display alternate names created by the user currently logged on.
890 891 892 893 894 895 896

The inherit flag is automatically cleared.


@item pgp-signature [11] (text)

Data is a PGP signature of the text. The signature should be the
David Byers's avatar
David Byers committed
897
equivalent of what "pgp -sba" in PGP 2.6.2 generates.
898 899 900 901 902 903 904 905

The secret, hide-creator and inherit bits are automatically cleared.
Signatures cannot be deleted once they have been created.


@item pgp-public-key [12] (letterbox)

Data is the public key of the person. It is desirable that the public
David Byers's avatar
David Byers committed
906 907 908
key contains a userid of the format "LysKOM <p@var{n}@@@var{server}>+",
where @var{n} is the number of the person in the LysKOM server specified
in @var{server}. This rule is currently not enforced.
909 910 911 912

This item can only be set by the person himself. The hide-creator,
secret and inherit bits are automatically cleared.

David Byers's avatar
David Byers committed
913

914 915
@item e-mail-address [13] (conference, letterbox, server)

David Byers's avatar
David Byers committed
916 917
Data is an RFC 822-style email address. When set on a mailbox, it
should be the email address of the person. If the person has multiple
918 919 920
email addresses he may set serveral e-mail-address aux-items.

The meaning of this aux-item when set on a conference that isn't a
David Byers's avatar
David Byers committed
921 922 923
mailbox is vague. For a conference that is used as to import a mailing
list this should be the email address of the list. For other conferences 
we haven't really defined a sensible use.
924 925

When this aux-item is set on the server it shold contain the email
926
address of the administrator (or administrators.)
927

David Byers's avatar
David Byers committed
928 929 930
This aux-item can only be set by the supervisor of a conference or the
server administrator. The creator cannot be hidden.

931 932 933 934

@item faq-text [14] (conference, server)

Data is a decimal text number, which is a FAQ for the conference (or
David Byers's avatar
David Byers committed
935 936
server). Creating an item of this type automatically causes creation of
a faq-for-conf item.
David Byers's avatar
David Byers committed
937 938 939 940

This item can only be set by the supervisor or server administrator. The 
hide-creator, secret, and inherit bits are automatically cleared.

941 942 943 944 945 946 947 948 949 950

@item creating-software [15] (text)

Data is the name and version number of the client that created the
text.  This aux-item can only be set by the author of the text.  Once
set, it cannot be removed or changed.  A typical value would be
@samp{elisp-client 0.47.3}.  Setting the creating-software aux-item is
optional.

The data should be the client name, a space, and the client version used
951
in the @reqlink{set-client-version} call.  The server may enforce this
952
restriction.
953

954
@item mx-author [16] (text)
955

956
Data is a string containing the name of the author of an imported
957 958 959 960 961 962
e-mail, extracted from the @code{From} header.  This aux-item may be
missing, if the mail address in the @code{From} header consists of just
the @code{addr-spec} (see the next aux-item).

Clients should display this instead of the actual author of the text
(which will be an importer ID) even if an mx-from aux-item is not present.
963

964 965
Sample contents: @code{Joe Q. Public} which may come from a @code{From}
header containing @code{"Joe Q. Public" <john.q.public@@example.com>}.
966

967
@item mx-from [17] (text)
968

969 970
Data is the proper e-mail address (called @code{addr-spec} in the mail
standards) extracted from the @code{From} header of an imported
971 972
e-mail. 

973 974
Clients should display this address together with the @aux{mx-author},
preferably inside angles. If @aux{mx-author} is not present, this address
975 976
should be shown anyway. It can also be used by clients to construct an
address for personal (e-mail) replies to an imported message.
977

978 979 980
Sample contents: @code{john.q.public@@example.com} which may come from a
@code{From} header containing @code{john.q.public@@example.com} or
something like @code{"Joe Q. Public" <john.q.public@@example.com>}.
981

982
@item mx-reply-to [18] (text)
983

984 985 986 987
Data is the proper e-mail address (called @code{addr-spec} in the mail
standards) extracted from the @code{Reply-To} header of an imported
e-mail. Clients should use this for constructing replies to imported
messages.
988

989
@item mx-to [19] (text)
990

991
Data is a single e-mail address from an email @code{To} header.
992
Multiple @aux{mx-to} items may be present when multiple recipients are
993 994
specified in the header. Clients should display these items along
with the normal LysKOM recipient headers.
995

996 997
Sample contents: Both @code{john.q.public@@example.com} and
@code{"Joe Q. Public" <john.q.public@@example.com>} are valid.
998

999
@item mx-cc [20] (text)
1000

1001
Same as @aux{mx-to}, but applies to the @code{CC} header rather than
1002
the @code{To} header.
1003

1004
@item mx-date [21] (text)
1005

1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
Data is the date and time from the @code{Date} header of an imported
email. Its format is "YYYY-MM-DD hh:mm:ss TZ". YYYY is the year the
message was sent, MM is the month, DD is the day, hh is the hour, mm is
the minute and ss is the second. This date and time are given in the
timezone where the message was sent. TZ is the timezone the date is
valid for. It must be of the form "+hhmm" or "-hhmm", where hh is the
number of hours offset from UTC and mm is the number of minutes
offset. Symbolic timezones are not permitted. The timezone specification
is recommended but optional, since it is not always available.

Clients should display this information as the date and time a text was
written, since the imported text will have been created at a later
time. The date and time when the mesage was imported would then be
displayed elsewhere or not at all.
1020

1021 1022
@item mx-message-id [22] (text)

1023 1024 1025
Data is the @code{Message-ID} header of an imported e-mail, with
whitespace and comments removed. The Message-ID should contain the
surrounding angles.
1026 1027 1028

@item mx-in-reply-to [23] (text)

1029 1030 1031
Data is a string containing one item of the same form as the
mx-message-id item described above. This is the Message-ID of
another mail the current text is a comment to.
1032

1033 1034 1035 1036 1037
Hopefully, this information comes from the @code{In-Reply-To} header
of the imported e-mail, but it could also have been picked from the end
of the @code{References} header line.

If the text really comments more than one other text directly, 
1038
it is allowed to attach more than one @aux{mx-in-reply-to} items to
1039
it.
1040 1041 1042

@item mx-misc [24] (text)

1043 1044 1045 1046 1047
Data is a string that contains all of the headers of an imported email,
including @code{Subject}, and including those that are redundantly
stored in other aux-items. The headers are concatenated with "\n". In
other words, this item contains all headers of an imported e-mail as
they appear in the message.
1048

1049
Clients are encouraged to provide a command to display this information.
1050

1051
@item mx-allow-filter [25] (conference, letterbox)
1052

1053 1054 1055
This aux-item has been declared obsolete. It was intended to supply
the importer with information on how to filter incoming messages
based on regular expressions matching header lines.
1056

1057
@item mx-reject-forward [26] (conference, letterbox)
1058

1059 1060 1061
This aux-item has been declared obsolete. It was intended 
to supplement mx-allow-filter by telling where rejected mails should
be sent.
1062

David Byers's avatar
David Byers committed
1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
@item notify-comments [27] (letterbox)

Data is a decimal text number that the user is interested in. Clients
should monitor this text for unread comments and present these to the
user in some convenient manner. This is typically used by users that
want to read comments to some text of theirs as soon as they arrive,
rather than in the normal reading order.

This item can only be set by the owner of the letterbox. No flags are
forced or cleared.
1073

David Byers's avatar
David Byers committed
1074 1075 1076 1077 1078 1079 1080 1081
@item faq-for-conf [28] (text)

Data is a decimal number specifying the conference a certain text is a
FAQ for. The special number zero denotes that the text is a FAQ for the
entire system. Items of this kind can only be created by the LysKOM
server itself. Texts with this item are protected from garbage
collection.

1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102
@item recommended-conf [29] (server)

Data is a decimal number specifying a conference that new members should
automatically be added to, optionally followed by a space and a
recommended priority, optionally followed by a space and a membership
type.  In the future, additional data may be defined; clients should
be prepared to accept and ignore a space and any trailing data that may
follow the membership type.

A few examples might clarify what the data may look like:
@table @code
@item 1
Conference number 1.
@item 2 32
Conference number 2, with priority 32.
@item 3 250 11100000
Conference number 3, with priority 250.  The membership should be
secret, passive and have the invitation bit set.
@item 4 253 01000000 garbage
Conference number 4, with priority 253.  The membership should be
passive.  The client should ignore the trailing garbage.  Note that
1103
clients are not allowed to create aux-items of this format, but the
1104 1105 1106 1107 1108
should be prepared to hande them correctly.
@end table

This is a recommendation only; it is up to the client that creates a new
person to also add him to the conferences that are specified via
1109
@aux{recommended-conf}.
1110

1111
@item allowed-content-type [30] (conference, letterbox, server)
1112 1113 1114 1115

Data is a non-negative decimal priority number, followed by a space,
followed by a LysKOM content type glob pattern.  Clients should send
texts to a conference only if the content-type matches any of the
1116
@aux{allowed-content-type} glob patterns of that conference.
1117

1118 1119 1120 1121
If the conference doesn't have any @aux{allowed-content-type}, the
@aux{allowed-content-type} items of the server should be used.  If the
server also has no @aux{allowed-content-type} aux-items, it should be
interpreted as if a single @aux{allowed-content-type} aux-item with the
1122
value @samp{1 text/plain} exists.
1123

1124
If there are @aux{allowed-content-type} aux-items with different
1125 1126
priority numbers, it is a hint to the client about which content-type is
most desirable.  Content-types that matches a lower priority number are
1127 1128 1129
preferred.

As an example, consider a conference with the following four
1130
@aux{allowed-content-type} aux-items:
1131 1132 1133 1134 1135 1136 1137 1138

@example
1 text/plain
2 x-kom/basic
2 text/enriched
3 text/*
@end example

1139 1140 1141 1142 1143
These aux-items taken together means that @samp{text/plain} is
preferred, that @samp{x-kom/basic} and @samp{text/enriched} can be
used if there is a reason why @samp{text/plain} is inadequate, and
that any text type (such as @samp{text/html}) is acceptable.  Other
content types, such as @samp{x-kom/user-area}, should not be used.
1144 1145 1146 1147 1148 1149 1150

The server does not currently enforce the above restriction on the
content type of new texts.  This mechanism is currently a hint to the
client (or to the author of a new text).  This may change in the
future, if experience shows that it is desirable to have the server
enforce the content type.

David Byers's avatar
David Byers committed
1151 1152
@end table

1153
@node Client-Specific Aux-Item Types
1154
@subsection Client-Specific Aux-Item Types
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168

Client-specific items do not cause the server to perform any magic. All
the flags (except the delete flag) are left untouched, the data is not
validated in any way, and anyone can create any item. If you need more
server support than this, your item should be on the predefined list.

All tags in the range 10000-19999 are reserved for clients. Blocks of
100 numbers at a time can be assigned to specific clients. A client
should never create items with tags in a range assigned to another
client or in an unassigned range. Assigned ranges will never change.

Currently, the following ranges are assigned to clients:
@itemize @bullet
@item 10000-10099: The Elisp Client
1169
@item 10100-10199: komimportmail
1170 1171