draft-ietf-llup-format-00.xml

Revision 25, 52.8 kB (checked in by m.david, 2 years ago)
this is the most recent state of the XML version of the specification. I will be changing the link on the main page, and at this stage, we should begin to use this as the primary focus for editing.

Line
1	<?xml version="1.0" encoding="UTF-8"?>
2	<?rfc toc="yes" ?>
3	<?rfc tocdepth="4" ?>
4	<?rfc private="" ?>
5	<!-- <?rfc editing="yes" ?> -->
6	<rfc xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
7	xsi:noNamespaceSchemaLocation="http://src.llup.org/vendor/IETF/RFC/2629/rfc2629.xsd"
8	category="exp" ipr="full3978" docName="draft-ietf-llup-format-00">
9	<front>
10	<title abbrev="LLUP Decentralized Messaging Protocol">LLUP Decentralized Messaging Protocol</title>
11	<author initials="R." fullname="Russ Miles" role="editor" surname="Miles">
12	<organization/>
13	<address>
14	<email>russellmiles@mac.com</email>
15	<uri>http://www.russmiles.com</uri>
16	</address>
17	</author>
18	<author initials="S." fullname="Sylvain Hellegouarch" role="editor" surname="Hellegouarch">
19	<organization/>
20	<address>
21	<email>sh@defuze.org</email>
22	<uri>http://www.defuze.org</uri>
23	</address>
24	</author>
25	<author initials="M.D." fullname="M. David Peterson" surname="Peterson">
26	<organization/>
27	<address>
28	<email>m.david@xmlhacker.com</email>
29	<uri>http://xmlhacker.com</uri>
30	</address>
31	</author>
32	<author initials="D." fullname="Don Demsak" surname="Demsak">
33	<organization/>
34	<address>
35	<email>don@donxml.com</email>
36	<uri>http://www.donxml.com</uri>
37	</address>
38	</author>
39	<author initials="K." fullname="Kurt Cagle" role="editor" surname="Cagle">
40	<organization/>
41	<address>
42	<email>kurt.cagle@gmail.com</email>
43	<uri>http://www.understandingxml.com</uri>
44	</address>
45	</author>
46	<author initials="U." fullname="Uche Ogbuji" surname="Ogbuji">
47	<organization/>
48	<address>
49	<email>uche.ogbuji@fourthought.com</email>
50	<uri>http://www.ogbuji.net</uri>
51	</address>
52	</author>
53	<author initials="P." fullname="Peter Saint-Andre" surname="Saint-Andre">
54	<organization/>
55	<address>
56	<email>stpeter@jabber.org</email>
57	<uri>http://www.jabber.org/people/stpeter.shtml</uri>
58	</address>
59	</author>
60	<author initials="J." fullname="Jason Kolb" surname="Kolb">
61	<organization/>
62	<address>
63	<email>jason.kolb@gmail.com</email>
64	<uri>http://www.jasonkolb.com</uri>
65	</address>
66	</author>
67	<author initials="R." fullname="Ralph Meijer " surname="Meijer">
68	<organization/>
69	<address>
70	<email>llup@ralphm.ik.nu</email>
71	<uri>http://ralphm.net/</uri>
72	</address>
73	</author>
74	<author initials="D." fullname="Dan Zambonini" surname="Zambonini">
75	<organization/>
76	<address>
77	<email>dan.zambonini@boxuk.com</email>
78	<uri>http://www.boxuk.com/</uri>
79	</address>
80	</author>
81	<date month="July" year="2006"/>
82	<keyword>LLUP</keyword>
83	<keyword>Blip</keyword>
84	<keyword>Decentralized</keyword>
85	<keyword>Messaging</keyword>
86	<abstract>
87	<t>This memo presents a protocol for decentralized messaging communication</t>
88	</abstract>
89	</front>
90	<middle>
91	<section title="Introduction" anchor="introduction">
92	<t>The World Wide Web has grown exponentially for the last decade to become today a
93	mandatory token in many fields. One of the greatest strength of the World Wild Web
94	is its capacitiy to let anyone having his word. One issue carried with that freedom
95	is that it has quickly become hard to look for relevant topic as well as to keep
96	track of resources.</t>
97	<t>One way to solve that problem is for the end user to make the effort to filter, sort
98	and organise using tools at hand such as browser bookmarks or email client filters.
99	However this has partly failed as well because the majority of people now using the
100	World Wide Web is not computer's litterate but takes the freedom concept behind the
101	Internet so strongly that they do not want to be forced to make effort to use it.
102	This explains the success of search engines. Searching a resource is made in a given
103	context from the user point of view, once found a resource is only interesting to
104	the user in that particular context. The user could organise and bookmark that
105	resource but what if the context does not occur for a long time? We believe that the
106	user would have to go through the process of searching a resource in the given
107	context all over again. In fact, he could well forget he had already bookmarked a
108	resource. To sum up users tend to think that the system is there to help them
109	retrieving what they look for with little effort. </t>
110	<t>As a side point of searching information, the user might want to be updated when a
111	resource he was interested in has been updated without having to come back to the
112	resource from time to time. That problem has already been taken into account with
113	blogs through the use of syndication feeds but we feel we can go further by making
114	the system simpler. LLUP aims to improve the user's experience of the World Wide Web
115	with little intrusion in his habits. Basically the user should only need to state
116	that he wants to hook onto a resource by letting the underlying system do the work
117	of tracking that resource and in return being pinged when that resource has changed.
118	One of the LLUP principle is to reduce bandwith pollution as well. For instance
119	currently the syndication feed system send the complete feed each time an entry has
120	been modified. LLUP instead would only ping regarding the entry which has changed.</t>
121	<section title="Namespace and Version" anchor="namespace">
122	<t>The XML namespace URI for the XML data format described in this specification is:</t>
123	<t>http://www.x2x2x.org/llup</t>
124	</section>
125	<section title="Notational Conventions">
126	<t>This specification uses the namespace prefix "llup:" for the Namespace URI
127	identified in the <xref target="namespace">section</xref> above. Note that the
128	choice of namespace prefix is arbitrary and not semantically significant.</t>
129	<t>LLUP is specified using terms from the XML Infoset <xref
130	target="W3C.REC-xml-infoset-20040204">W3C.REC-xml-infoset-20040204</xref>.
131	However, this specification uses a shorthand for two common terms; the phrase
132	"Information Item" is omitted when naming Element Information Items and
133	Attribute Information Items. Therefore, when this specification uses the term
134	"element," it is referring to an Element Information Item in Infoset terms.
135	Likewise, when it uses the term "attribute," it is referring to an Attribute
136	Information Item.</t>
137	<t>Some sections of this specification are illustrated with fragments of a
138	non-normative RELAX NG Compact schema [RELAX-NG]. However, the text of this
139	specification provides the definition of conformance. A complete schema appears
140	in Appendix</t>
141	<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
142	"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
143	interpreted as described in BCP 14, <xref target="refs.RFC2119">RFC2119</xref>,
144	as scoped to those conformance targets.</t>
145	</section>
146	</section>
147	<section title="Architecture">
148	<t> In order to meet the full set of concerns identified in the problem statement and
149	purpose of LLUP (see the previous section of this specification), the architecture
150	of LLUP needs to be specified at a generic level such that it is not tied to one
151	particular implementation technology. As such, the high-level architecture of LLUP
152	can be broken into a distinct set of services. Services provide an ideal means of
153	concentrating on the functional capabilities of LLUP without having to specify
154	particular implementation protocols or technologies; the focus is on the breakdown
155	of concerns rather than how those concerns are actually brought to life in a given
156	target domain. Each service that makes up part of the high-level LLUP architecture
157	needs to be described in terms of it's functions, the messages that it supports and
158	how it then interacts with the other services in order to play it's part in the
159	overall architecture. </t>
160	<section title="Generic services">
161	<t> Three key characteristics are essential to the way that the LLUP generic
162	services are described. The service definitions presented here should provide a
163	framework by which the services can: <list style="symbols">
164	<t>Be accurately implemented by a given system such that it can claim to be
165	implementing LLUP.</t>
166	<t>Support a myriad of possible presentation techniques and features that
167	can then be applied to take advantage of LLUP from a user and system
168	configuration perspective. </t>
169	</list></t>
170	<t>The aim is that the following services definitions can be used by any system that
171	sees a value in adopting LLUP, without unduly constraining the implementation of
172	the protocol and hence its applicability to a target domain. LLUP contains three
173	distinct services: <list style="symbols">
174	<t>The Publication Service: A means of creating new BLIPs.</t>
175	<t>The Subscription Service: A means of subscribing to specific types of
176	BLIPs.</t>
177	<t>The BlogXast Service: A means of routing BLIPS intelligently in order to
178	create a form of information transmission topology.</t>
179	</list></t>
180	<section title="BLIP">
181	<t>At the heart of any deployment of the LLUP services is the concept of a BLIP.
182	A BLIP is analogous to an entry in a traditional ATOM new feed. A BLIP
183	contains enough information to enable the LLUP services to understand and
184	intelligently route the BLIP to those endpoints that are interested in the
185	information that the BLIP contains. A BLIP can be used to either wrap the
186	actual content to which it is referring, or a simple reference to more
187	complex content that can be retrieved by the receiving end point as and when
188	they deem it appropriate. The LLUP architecture's whole purpose is to
189	support the creation, routing and reception of BLIPS. </t>
190	<section title="Publication service">
191	<t>The LLUP publication service's core purpose is to provide a means of
192	creating new LLUP-complicant messages (or BLIPS) in order to inform a
193	LLUP enabled system that there is either new content available or to
194	simply intelligently broadcast a notification. A BLIP may reference a
195	set resource or simply encapsulate a notification, for the purposes of
196	the publication service either type of BLIP will be accepted. A
197	publication service may implement BLIP acceptance policies or even user
198	accounts, this is entirely up to the service implementation. </t>
199	</section>
200	<section title="Subscription service">
201	<t>The LLUP subscription service's core purpose is to provide a means for
202	systems to express an interest in receiving certain types of BLIP. With
203	existing news feeds, the entire feed needs to be retrieved to decide
204	what has changed. Contrasting with this type of approach, a subscription
205	service only the BLIPs that are of interest will be received and only
206	when new information has been made available.</t>
207	</section>
208	<section title="Blogxast service">
209	<t>The LLUP blogxast service is the most critical part of the LLUP
210	architecture. At its most simplest, a blogXast service can accept BLIP's
211	and the intelligently transmit those BLIPs on depending on BLIP content
212	and the internal service configuration.</t>
213	<t>A blogXast service can be thought of as being a combination of a
214	publication service and a subscription service. It is a subscription
215	service as it will only forward BLIPSs to further end points according
216	to subscription information about those end points. It has the
217	characteristics of a publication service because it can accept new BLIPs
218	that are transmitted to it.</t>
219	<t>The power of a blogXast service is in the fact that it offers a form of
220	intelligent router for BLIPs. In a simple configuration, as shown in
221	Figure 1 below, a BlogXast service can be chained in-between a
222	subscription and publication service. [TBD] need to place a figure here
223	to show a simple blogxast service sitting in-between a publication and
224	subscriptions service. Although this is the simplest configuration this
225	does not really demonstrate the real power of the blogxast service.
226	Remembering that a blogxast service can filter the blips it receives (as
227	a form of publication service) and route them onto end points that have
228	expressed an interest on a particular type of BLIP (using the
229	subscription characteristics), because of the way that bloXast looks
230	like a combination of these service it can itself be chained together to
231	form an intelligent network topology; intelligent because it routes
232	messages based on content and allows full control over the lifecycle of
233	BLIPs, removing the problems of broadcasting: redundant transmissions
234	(messages can be recognised and if already received then not
235	re-transmitted) and transmission of irrelevant content (messages are
236	targeted to only those end points that have expressed an interest so
237	that services don't receive messages when they are not required or
238	interesting).</t>
239	</section>
240	</section>
241	</section>
242	</section>
243	<section title="LLUP Elements Definition">
244	<t>This section explains the different elements available to the LLUP messaging
245	protocol.</t>
246	<section title="Common elements">
247	<section title="The "llup:sender" element">
248	<t>(description here)</t>
249	<figure anchor="llup_sender" title="The llup:sender element">
250	<artwork><![CDATA[
251	llupSender =
252	element llup:sender {
253	attribute credentia-id { text },
254	attribute email { text },
255	text
256	}
257	]]>
258	</artwork>
259	</figure>
260	</section>
261	<section title="The "llup:recipients" element">
262	<t>(description here)</t>
263	<figure anchor="llup_recipients" title="The llup:recipients element">
264	<artwork><![CDATA[
265	llupRecipients =
266	element llup:recipients {
267	llupRecipient+
268	}
269	]]>
270	</artwork>
271	</figure>
272	<t>The following child elements are defined by this specification:</t>
273	<t>
274	<list style="symbols">
275	<t>llup:recipients element MUST contain one or more llup:recipient
276	element(s)</t>
277	</list>
278	</t>
279	</section>
280	<section title="The "llup:recipient" element">
281	<t>(description here)</t>
282	<figure anchor="llup_recipient" title="The llup:recipient element">
283	<artwork><![CDATA[
284	llupRecipient =
285	element llup:recipient {
286	text
287	}
288	]]>
289	</artwork>
290	</figure>
291	</section>
292	<section title="The "llup:time-span" element">
293	<t>(description here)</t>
294	<figure anchor="llup_time_span" title="The llup:time-span element">
295	<artwork><![CDATA[
296	llupTimeSpan =
297	element llup:time-span {
298	attribute start { xsd:dateTime },
299	attribute expires { xsd:dateTime }
300	}
301	]]>
302	</artwork>
303	</figure>
304	</section>
305	<section title="The "llup:keywords" element">
306	<t>(description here)</t>
307	<figure anchor="llup_keywords" title="The llup:keywords element">
308	<artwork><![CDATA[
309	llupKeywords =
310	element llup:keywords {
311	llupKeyword+
312	}
313	]]>
314	</artwork>
315	</figure>
316	<t>The following child elements are defined by this specification:</t>
317	<t>
318	<list style="symbols">
319	<t>llup:keywords element MUST contain one or more llup:keyword
320	element(s)</t>
321	</list>
322	</t>
323	</section>
324	<section title="The "llup:keyword" element">
325	<t>(description here)</t>
326	<figure anchor="llup_keyword" title="The llup:keyword element">
327	<artwork><![CDATA[
328	llupKeyword =
329	element llup:keyword {
330	text
331	}
332	]]>
333	</artwork>
334	</figure>
335	</section>
336	<section title="The "llup:home" element">
337	<t>(description here)</t>
338	<figure anchor="llup_home" title="The llup:home element">
339	<artwork><![CDATA[
340	llupHome =
341	element llup:home {
342	text
343	}
344	]]>
345	</artwork>
346	</figure>
347	</section>
348	<section title="The "llup:admin" element">
349	<t>(description here)</t>
350	<figure anchor="llup_admin" title="The llup:admin element">
351	<artwork><![CDATA[
352	llupAdmin =
353	element llup:admin {
354	text
355	}
356	]]>
357	</artwork>
358	</figure>
359	</section>
360	<section title="The "llup:link" element">
361	<t>(description here)</t>
362	<figure anchor="llup_link" title="The llup:link element">
363	<artwork><![CDATA[
364	llupLink =
365	element llup:link {
366	text
367	}
368	]]>
369	</artwork>
370	</figure>
371	</section>
372	<section title="The "llup:subject" element">
373	<t>(description here)</t>
374	<figure anchor="llup_subject" title="The llup:subject element">
375	<artwork><![CDATA[
376	llupSubject =
377	element llup:subject {
378	text
379	}
380	]]>
381	</artwork>
382	</figure>
383	</section>
384	<section title="The "llup:history" element">
385	<t>(description here)</t>
386	<figure anchor="llup_history" title="The llup:history element">
387	<artwork><![CDATA[
388	llupHistory =
389	element llup:history {
390	attribute created { xsd:dateTime },
391	attribute last-update { xsd:dateTime }
392	}
393	]]>
394	</artwork>
395	</figure>
396	</section>
397	<section title="The "llup:standingblip" element">
398	<t>(description here)</t>
399	<figure anchor="llup_standingblip" title="The llup:standingblip element">
400	<artwork><![CDATA[
401	llupStandingBlip =
402	element llup:standingblip {
403	llupSender,
404	llupHome
405	}
406	]]>
407	</artwork>
408	</figure>
409	<t>The following child elements are defined by this specification:</t>
410	<t>
411	<list style="symbols">
412	<t>llup:standingblip element MUST contain one llup:sender element</t>
413	<t>llup:standingblip element MUST contain one llup:home element</t>
414	</list>
415	</t>
416	</section>
417	<section title="The "llup:blipconsumer" element">
418	<t>(description here)</t>
419	<figure anchor="llup_blipconsumer" title="The llup:blipconsumer element">
420	<artwork><![CDATA[
421	llupBlipConsumer =
422	element llup:blipconsumer {
423	llupSender,
424	llupHome
425	}
426	]]>
427	</artwork>
428	</figure>
429	<t>The following child elements are defined by this specification:</t>
430	<t>
431	<list style="symbols">
432	<t>llup:blipconsumer element MUST contain one llup:sender element</t>
433	<t>llup:blipconsumer element MUST contain one llup:home element</t>
434	</list>
435	</t>
436	</section>
437	<section title="The "llup:receiveblipendpoint" element">
438	<t>(description here)</t>
439	<figure anchor="llup_receiveblipendpoint"
440	title="The llup:receiveblipendpoint element">
441	<artwork><![CDATA[
442	llupReceiveBlipEndPoint =
443	element llup:receiveblipendpoint {
444	text
445	}
446	]]>
447	</artwork>
448	</figure>
449	</section>
450	<section title="The "llup:addblipconsumerendpoint" element">
451	<t>(description here)</t>
452	<figure anchor="llup_addblipconsumerendpoint"
453	title="The llup:addblipconsumerendpoint element">
454	<artwork><![CDATA[
455	llupAddBlipConsumerEndPoint =
456	element llup:addblipconsumerendpoint {
457	text
458	}
459	]]>
460	</artwork>
461	</figure>
462	</section>
463	<section title="The "llup:publicationservice" element">
464	<t>(description here)</t>
465	<figure anchor="llup_publicationservice"
466	title="The llup:publicationservice element">
467	<artwork><![CDATA[
468	llupPublicationService =
469	element llup:publicationservice {
470	text
471	}
472	]]>
473	</artwork>
474	</figure>
475	</section>
476	</section>
477	<section title="Subscription Elements">
478	<section title="The "llup:subscribe" element">
479	<t>(description here)</t>
480	<figure anchor="llup_subscribe" title="The llup:subscribe element">
481	<artwork><![CDATA[
482	llupSubscribe =
483	element
484	llup:subscribe {
485	llupSender,
486	llupRecipients,
487	llupTimeSpan
488	}
489	]]>
490	</artwork>
491	</figure>
492	<t>The following child elements are defined by this specification:</t>
493	<t>
494	<list style="symbols">
495	<t>llup:subscribe element MUST contain one llup:sender element</t>
496	<t>llup:subscribe element MUST contain one llup:recipients element</t>
497	<t>llup:subscribe element MUST contain one llup:timespan element</t>
498	</list>
499	</t>
500	</section>
501	<section title="The "llup:subscription" element">
502	<t>(description here)</t>
503	<figure anchor="llup_subscription" title="The llup:subscription element">
504	<artwork><![CDATA[
505	llupSubscription =
506	element
507	llup:subscription {
508	llupSender,
509	llupHome
510	}
511	]]>
512	</artwork>
513	</figure>
514	<t>The following child elements are defined by this specification:</t>
515	<t>
516	<list style="symbols">
517	<t>llup:subscription element MUST contain a llup:sender element</t>
518	<t>llup:subscription element MUST contain a llup:home element</t>
519	</list>
520	</t>
521	</section>
522	<section title="The "llup:cancelsubscription" element">
523	<t>(description here)</t>
524	<figure anchor="llup_cancelsubscription"
525	title="The llup:cancelsubscription element">
526	<artwork><![CDATA[
527	llupCancelSubscription =
528	element
529	llup:cancelsubscription {
530	llupSender,
531	llupHome
532	}
533	]]>
534	</artwork>
535	</figure>
536	<t>The following child elements are defined by this specification:</t>
537	<t>
538	<list style="symbols">
539	<t>llup:cancelsubscription element MUST contain a llup:sender element</t>
540	<t>llup:cancelsubscription element MUST contain a llup:home element</t>
541	</list>
542	</t>
543	</section>
544	<section title="The "llup:subscriptioncancelled" element">
545	<t>(description here)</t>
546	<figure anchor="llup_subscriptioncancelled"
547	title="The llup:subscriptioncancelled element">
548	<artwork><![CDATA[
549	llupSubscriptionCancelled =
550	element
551	llup:subscriptioncancelled {
552	llupSender,
553	llupAdmin
554	}
555	]]>
556	</artwork>
557	</figure>
558	<t>The following child elements are defined by this specification:</t>
559	<t>
560	<list style="symbols">
561	<t>llup:cancelsubscription element MUST contain a llup:sender element</t>
562	<t>llup:cancelsubscription element MUST contain a llup:admin element</t>
563	</list>
564	</t>
565	</section>
566	</section>
567	<section title="Publication elements">
568	<section title="The "llup:addpublicationservice" element">
569	<t>(description here)</t>
570	<figure anchor="llup_addpublicationservice"
571	title="The llup:addpublicationservice element">
572	<artwork><![CDATA[
573	llupAddPublicationService =
574	element llup:addpublicationservice {
575	attribute origin { text },
576	attribute id { text },
577	llupSender,
578	llupTimeSpan,
579	llupAddBlipConsumerEndPoint
580	}
581	]]>
582	</artwork>
583	</figure>
584	<t>The following child elements are defined by this specification:</t>
585	<t>
586	<list style="symbols">
587	<t>llup:addpublicationservice element MUST contain a llup:sender element</t>
588	<t>llup:addpublicationservice element MUST contain a llup:timespan
589	element</t>
590	<t>llup:addpublicationservice element MUST contain a
591	llup:addblipconsumerendpoint element</t>
592	</list>
593	</t>
594	</section>
595	<section title="The "llup:publicationserviceadded" element">
596	<t>(description here)</t>
597	<figure anchor="llup_publicationserviceadded"
598	title="The llup:publicationserviceadded element">
599	<artwork><![CDATA[
600	llupPublicationServiceAdded =
601	element llup:addpublicationservice {
602	llupSender,
603	llupPublicationService
604	}
605	]]>
606	</artwork>
607	</figure>
608	<t>The following child elements are defined by this specification:</t>
609	<t>
610	<list style="symbols">
611	<t>llup:publicationserviceadded element MUST contain a llup:sender
612	element</t>
613	<t>llup:publicationserviceadded element MUST contain a
614	llup:publicationservice element</t>
615	</list>
616	</t>
617	</section>
618	<section title="The "llup:removepublicationservice" element">
619	<t>(description here)</t>
620	<figure anchor="llup_removepublicationservice"
621	title="The llup:removepublicationservice element">
622	<artwork><![CDATA[
623	llupRemovePublicationService =
624	element llup:removepublicationservice {
625	attribute id { text },
626	llupSender,
627	llupPublicationService
628	}
629	]]>
630	</artwork>
631	</figure>
632	<t>The following child elements are defined by this specification:</t>
633	<t>
634	<list style="symbols">
635	<t>llup:removepublicationservice element MUST contain a llup:sender
636	element</t>
637	<t>llup:removepublicationservice element MUST contain a
638	llup:publicationservice element</t>
639	</list>
640	</t>
641	</section>
642	<section title="The "llup:publicationserviceremoved" element">
643	<t>(description here)</t>
644	<figure anchor="llup_publicationserviceremoved"
645	title="The llup:publicationserviceremoved element">
646	<artwork><![CDATA[
647	llupRemovePublicationService =
648	element llup:removepublicationservice {
649	llupSender,
650	llupAdlin
651	}
652	]]>
653	</artwork>
654	</figure>
655	<t>The following child elements are defined by this specification:</t>
656	<t>
657	<list style="symbols">
658	<t>llup:publicationserviceremoved element MUST contain a llup:sender
659	element</t>
660	<t>llup:publicationserviceremoved element MUST contain a
661	llup:publicationservice element</t>
662	</list>
663	</t>
664	</section>
665	</section>
666	<section title="BLIP elements">
667	<section title="The "llup:createblip" element">
668	<t>(description here)</t>
669	<figure anchor="llup_createblip" title="The llup:createblip element">
670	<artwork><![CDATA[
671	llupCreateBlip =
672	element llup:createblip {
673	attribute origin { text },
674	attribute id { text },
675	llupSender,
676	llupRecipients,
677	llupLink,
678	llupSubject,
679	llupTimeSpan,
680	llupKeywords
681	}
682	]]>
683	</artwork>
684	</figure>
685	<t>The following child elements are defined by this specification:</t>
686	<t>
687	<list style="symbols">
688	<t>llup:createblip element MUST contain a llup:sender element</t>
689	<t>llup:createblip element MUST contain a llup:recipients element</t>
690	<t>llup:createblip element MUST contain a llup:link element</t>
691	<t>llup:createblip element MUST contain a llup:subject element</t>
692	<t>llup:createblip element MUST contain one llup:timespan element</t>
693	<t>llup:createblip element SHOULD contain one llup:keywords element</t>
694	</list>
695	</t>
696	</section>
697	<section title="Standing BLIP elements">
698	<section title="The "llup:createstandingblip" element">
699	<t>(description here)</t>
700	<figure anchor="llup_createstandingblip"
701	title="The llup:createstandingblip element">
702	<artwork><![CDATA[
703	llupCreateBlip =
704	element llup:createstandingblip {
705	attribute origin { text },
706	attribute id { text },
707	llupSender,
708	llupRecipients,
709	llupLink,
710	llupSubject,
711	llupTimeSpan,
712	llupKeywords
713	}
714	]]>
715	</artwork>
716	</figure>
717	<t>The following child elements are defined by this specification:</t>
718	<t>
719	<list style="symbols">
720	<t>llup:createstandingblip element MUST contain a llup:sender
721	element</t>
722	<t>llup:createstandingblip element MUST contain a llup:recipients
723	element</t>
724	<t>llup:createstandingblip element MUST contain a llup:link element</t>
725	<t>llup:createstandingblip element MUST contain a llup:subject
726	element</t>
727	<t>llup:createstandingblip element MUST contain one llup:timespan
728	element</t>
729	<t>llup:createstandingblip element SHOULD contain one llup:keywords
730	element</t>
731	</list>
732	</t>
733	</section>
734	<section title="The "llup:cancelstandingblip" element">
735	<t>(description here)</t>
736	<figure anchor="llup_cancelstandingblip"
737	title="The llup:cancelstandingblip element">
738	<artwork><![CDATA[
739	llupCancelStandingBlip =
740	element llup:cancelstandingblip {
741	attribute origin { text },
742	attribute id { text },
743	llupSender,
744	llupStandingBlip
745	}
746	]]>
747	</artwork>
748	</figure>
749	<t>The following child elements are defined by this specification:</t>
750	<t>
751	<list style="symbols">
752	<t>llup:cancelstandingblip element MUST contain a llup:sender
753	element</t>
754	<t>llup:cancelstandingblip element MUST contain a llup:standingblip
755	element</t>
756	</list>
757	</t>
758	</section>
759	<section title="The "llup:standingblipcancelled" element">
760	<t>(description here)</t>
761	<figure anchor="llup_standingblipcancelled"
762	title="The llup:standingblipcancelled element">
763	<artwork><![CDATA[
764	llupStandingBlipCancelled =
765	element
766	llup