and often does.

Terminology may vary from program to program, but “empty set” or “empty” originally referred to only to the backfield and still does in many programs.

Here’s an article about why a school specifically uses one or even two tight ends to block when they’re are going “empty”.



Here’s the Steelers using an empty set with an attached tight end:



In general “empty” means the QB has no one back by him to hand off to. The closest you get to a pure passing set.

Others now use “empty” to also mean no attached tight ends as well as no backs in the backfield, but that would be a more specific and limited meaning specific to their program.