No, I mean "generic" in the sense that we already have a foreign key here to a Session object and not to a TrainingSession object :)

My only problem here is, that the field is named "trainings" while the `SCHEDULE_ATTENDING_POSSIBLE` setting does not necessarily have to include trainings. Also, this kind of section is named differently every couple of years. Once not to long ago we called "trainings" "tutorials". Eventually they might end up being named "workshops" (like e.g. at FluentConf). If we name that field for instance `sessions_attending` and just called it "Trainings" in the UI, we don't have to migrate or live with an obsolete data structure when that happens (and I'm pretty sure it will :)).