1. The use, esp. on Twitter by
Craig Hockenberry (after whom the technique is named), of caps
lock, no punctuation, and occasional misspellings to represent the speech of a somewhat mentally inferior alter
ego.
2. The Caps Lock key itself when used as in 1.
3. A fictional key (or setting) actually labeled "CHOCK LOCK" on a keyboard (or in an app), usually replacing Caps Lock.