Thread:Support/"Deprecated" in Flagged Revisions

There are several messages in the group All Flagged Revs Messages that use the word "deprecated" or "deprecation".

I understand what is, for example, a "deprecated keyword" in the Perl programming language - it's a keyword that is OK in version 4.0, but is not recommended for use in version 5.8. But what exactly does it mean in Flagges Revisions? Is it the same as "rejected" or something else?

It would be nice if someone could document it. Thank you.