trailing star/double star in --exclude

[Denis Solovyov]

Is there any difference in rsync behaviour between "--exclude /dir/*"
and "--exclude /dir/**" (one and two trailing "stars")?

Will rsync enter and scan content of dir/ (and thus change access time
of files and directories) in any of these examples?

Here in list rsync users show both variants in their examples, on
practice I see no difference, but maybe there is a recommended (i.e.
more "ideologically" correct) one?

With the best regards,
Denis Solovyov