Under the Powered by You section on the FAQ, the text “This site is operated by your friendly local staff […] contact us via the staff page.” is present which links to c.osm.org/about which has a list of site admins and moderators.
@SomeoneElse has a mod shield icon, a “Support moderator” label, and a user description that begins with “As a moderator on this site” - but is not in the site mod list. Is that list out-of-date, or does it intentionally not list some moderators?
As far as I know there are admins, global moderators and category moderators. The last ones are not displayed on that page. They can only moderate in their sub category. User SomeoneElse for example can only moderate in the Help and support category.