Spring Training patches

What is the purpose of teams having spring training patches? Is it for marketing? Hats and jerseys have them, but not pants? Umps don't wear them. Do spring jerseys jerseys get recycled for use the following spring training? Do they go to the minor leagues. I do see that some make it to the collector market. I remember decades ago when actual [season] game jerseys from the previous years (s) were used in spring training. Seems like teams now have jerseys just for spring training only. Are the batting helmets used only for Spring Training?

The AZ and FL patches first appeared in 2016, on BP-style jerseys that were generally used as game jerseys in spring games. Prior to that, a lot of teams, since the mid-1980s, just wore their BP shirts for games in spring. Even now, there are a few exceptions (though very few). So far, the Cubs have been wearing their spring game jerseys only for road contests, and have been wearing their regular home game jerseys (albeit possibly a special set) for games in Mesa. The Dodgers also wore home game jerseys for their opener against the White Sox in the stadium both use (Camelback Ranch)...the Dodgers were designated as the home team. The prior year jerseys usage was the norm before BP jersey became accepted spring game attire, and the idea pretty much died in or slightly after 2000, with teams that did still use game jerseys in FL and AZ (Cardinals, Tigers, and others) issuing special sets for March games.

Dave Miedema