rsync by path/filename only?

Question

Is there a way for me to rsync two directories comparing only filenames (and not file size, date modified, or any other criteria)?

Answer 1

From the rsync(1) man page:

        --ignore-existing       skip updating files that exist on receiver

Answer 2

The --ignore-times option should do that.

From man rsync:

-I, --ignore-times
Normally rsync will skip any files that are already the same size and have the same modification timestamp. This option turns off this “quick check” behavior, causing all files to be updated.