There have been some requests to make it possible for Mastodon users to create threads on Lemmy. At the moment this is not possible because Mastodon cant set the title field which is mandatory in Lemmy. The same problem affects other projects like Pleroma or Friendica (where title is optional).
It is unlikely that Mastodon would make any change in this regard, so a workaround in Lemmy would be necessary. I implemented such a workaround which makes the title optional when receiving a federated post, and uses the first line of the content instead. This workaround could also be made configurable per instance or per community.
But to be honest I am not sure the workaround is a good idea in general, as it could result in bad titles, and generally more low-quality posts. Thats why I want to know what the community thinks about it.
Just thinking out loud: Does ActivityPub say anything about titles? I’m asking as I don’t know, but I am also thinking whichever route that is the closest to “the standard” probably should be the preferred route.
Ideally all Fediverse services should be using an as-close-as-possible interpretation of ActivityPub. If that standard in turn is lacking, that is the problem that should be solved.
The Fediverse in general and Mastodon in particular lack the functionality of “groups”, which surely is one of the most asked-for features for both Mastodon and the rest of the services. With Lemmy the Fediverse can get groups (of sorts). However, if Lemmy bend-over backwards just for Mastodon it might set a precedence in “you/me/we are all on Mastodon” as opposed to “we are all in the Fediverse, using ActivityPub”.
If on the other hand “everyone but Mastodon” is (or could be) using titles already, the Mastodon leadership (hah) has to look at how badly they want the groups-functionality, and if they therefore would be willing to adapt to Lemmy, ActivityPub and the rest of the services that are closer to the actual standard.
The Activitypub standard doesnt mandate any specific properties, not the title and not even the content which Mastodon sends. Thats one problem with Activitypub, you can send almost anything you want and its technically valid (even if no other platform can handle it). However the presence or lack of a title isnt really related to groups.