aptus

typically these are meant to convey intent, not enforce invariants; often sufficient to replace a comment.

to convey something is final conceptually in the corner case of multiple inheritance

to convey that something isn't meant to remain in production code

to convey explicitly that something is intended to be overriden in some situations (as opposed to having forgotten to make it final).

to convey that the order of the following code is important

in cases where should be sealed but can't because we refactored some code to another file for clarity