the Slug header should not be mandatory
According to the AtomPub specification, this header is not mandatory :
9.7. The Slug Header
Slug is an HTTP entity-header whose presence in a POST to a Collection constitutes a request by the client to use the header's value as part of any URIs that would normally be used to retrieve the to-be-created Entry or Media Resources.
Servers MAY use the value of the Slug header when creating the Member URI of the newly created Resource, for instance, by using some or all of the words in the value for the last URI segment. Servers MAY also use the value when creating the atom:id, or as the title of a Media Link Entry (see Section 9.6).
Servers MAY choose to ignore the Slug entity-header. Servers MAY alter the header value before using it. For instance, a server might filter out some characters or replace accented letters with non- accented ones, replace spaces with underscores, change case, and so on.
And the SWORDv2 specify that:
Server implementations MUST adopt the behaviour and requirements in Section 9.7 of [AtomPub] with respect to the Slug header
See also T2740, #2752 (closed) and ceb38e95
Migrated from T2757 (view on Phabricator)