They always made the anouncement that there should be no lettering on tee-shirts. If you came to a site with lettering or advertisements on your shirt you would be asked to turn it in-side-out.
Also, the one Elder always enjoyed making an anouncement about sisters and "low-cut" tee-shirts. Evidently that was a no-no. I only went to one quick build, and was on garbage detail. Not much fun. Was hoping I could be part of the "tee-shirt" police squad.