A worker employed at a dry-cleaning establishment to remove spots.

A worker employed to apply spots (as markers or identifiers).

A person employed to keep watch for some anticipated event.

synonyms: lookout, lookout man, picket, scout, sentinel, sentry, watch.

Dutch: wacht, schildwacht, uitkijk, verkenner
Polish: wartownik

Someone who is the first to observe something.

synonyms: discoverer, finder.

Dutch: vinder
Polish: odkrywca