[topicmapmail] DM zero source locators

[Lars Marius Garshol]

* Kal Ahmed
| 
| Topics are different - they have multiple identities: the source
| locator, the subject indicator and the subject address. AFAIK the
| practice when using subjectIndicatorRef in instanceOf is to call
| into existence a topic which has the specified URI as a subject
| indicator, but not necessarily any source locator. Because you *can*
| identify topics through their subject indicators, this is not really
| a problem (e.g. in tolog you can use a subject indicator as a query
| parameter).
| 
| Other information items are different - if an occurrence information
| item has no source locator, it cannot be addressed. To my mind, the
| question is whether the DM should *require* a source locator for all
| information items. My feeling is that being permissive is a good
| thing in this case - if your system requires an item to be
| addressable, give it a source locator, but I would be wary about
| requiring TM processors to augment the DM with source locators, not
| least because such locators are not required by XTM syntax.

Amen. There isn't really that much more to say about this, I think.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >