(1) A sort of light that projects a texture onto an area of a surface, completely replacing that surface's own texture, over a set area. (Some other 3D packages have them.) E.g. it seems to be a handy way to put badges on a man's shoulders, where the usual human texture mapping split between front and back makes applying shoulder badges by texture mapping impossible.

(2) Bryce-type booleaning, e.g. making a hole in something by booleaning 2 objects "A and not B", where A is an object, and B is a cylinder the shape of the hole.