Feature Request

originally posted in atk4/ui#2129

Currently, the empty form rule is very, very confusing as the logic is negated with the remaining names.

empty means "nothing", but the rule validates the form field is "filled / not empty".

here atk4/ui#2129 (comment) is this fact more evident when compared with other rules like checked or is[dog]

This is a feature request to rename empty form rule to something like notEmpty or mandatory. For BC, the empty can be kept with a console warning.