FEP-9f9f: Collections has been published:

https://codeberg.org/fediverse/fep/src/branch/main/fep/9f9f/fep-9f9f.md

It seems to cover the basics, let me know if I missed anything.

#fep

RE: https://socialhub.activitypub.rocks/ap/object/4f422d20555601ca6e73b35b830cf74d