Definitions:
Cleat: a ladder crosspiece of rectangular cross section placed on edge. A person steps on a cleat while ascending or descending a ladder.
[29 CFR 1926.1050(b)]
Extension trestle ladder: a self-supporting portable ladder, adjustable in length, consisting of a trestle ladder base and a vertically adjustable extension section, with a suitable means for locking the ladders together.
Portable ladder: a ladder that can be readily moved or carried.
Step stool (ladder type): a self-supporting, foldable, portable ladder, nonadjustable in length, 32 inches or less in overall size, with flat steps and without a pail shelf, designed to be climbed on the ladder top cap as well as all steps. The side rails may continue above the top cap.