Tapped the title to read the punch line.

Saw no punch line.

Re-read the title...

shame

This took me longer than I would like to admit to process

The reverse works only when read aloud:

Shout into all the people wondering what the opposite of out is.

Unless you're in a library.

Shout out to all the dawgs that left a mess on the carpet

to those who didn't get it: Shout "out"