Use a Slug: header to allow a client to request that a string be included in a new entry's URI
Many existing weblog software implementations allow clients to request specific URI content entries. APP should also support this capability
Using a header allows this capability to be used for both entry and media colllections.
Avoiding the Content-Disposition header avoids the complexity engendered by that headers semantics.
8.1.3 The Slug header
When posting to a collection a client may include a Slug header. This constitutes a request by the client that the URI assigned to the new resource incorporate string provided in the value of the Slug. Server implementations MAY attempt to comply with the request.
Server implementations are more likely to be able to incorporate requested strings if they are constructed with sensitivity to IRI syntax rules [RFC3987]. In particular, strings containing characters with syntactic significance, in particular the path-separator character "/", are apt to cause server implementations difficulty.
Servers MUST accept a header value encoded according to RFC2184 conventions for long values or charset encodings.
This specification assigns no significance to the Slug: header outside of POSTing to a collection.