How to advertise free text item search for only specific collections

[ycespb]

It appears that the conformance classes apply throughout the catalog, and thus to all collections. e.g. the conformance class https://api.stacspec.org/v1.0.0-rc.1/ogcapi-features#free-text (declared in the landing page / root catalog) advertises that free text (item) search is supported for all collections (i.e. at their rel="items" endpoint via a q parameter). Is this understanding correct ?

Is it possible with the proposed extension to also cover the use case where I would like to advertise the support for free-text (item) search only for a limited number of collections in the catalog ? Is there a way to express this ? Can this be advertised by declaring the same conformance class, not in the landing page, but via a conformsTo property in the STAC collection metadata for that specific collection or is it mandatory/assumed that all conformance class declarations are to appear in the root catalog/landing page ?

[m-mohr]

Not yet, but I think in the future there might be ways to add conformsTo to collections. At least I think I've seen OGC drafting something like that.