I’d like to be able to create a relation that accepts only a certain list of options as a value, that can be picked via a dropdown menu. This could be set as either accepting a single value or multiple (allowing user to select/unselect).
The reason I’d want this isn’t so much to limit the choices (though this could be useful), but to help me know/remember what options I want to be choosing from for that relation.
I’d even like to be able to add new options to the list easily (maybe the last option of the list would be “Add to list”).
An alternative implementation could be to be simply to use the tag type, but add ability to show all available tags in a dropdown menu when the field is clicked.
Still, the option of making a relation accept only 1 value at a time would be very useful. Currently there’s no way to do this (unless you use tags and remember not to add more than one for that relation).