Naming a Single Sticker

A piece has several stickers (one per face it touches). To name a single sticker, write the face it sits on first, then the rest of the piece.

Example — the DF edge has two stickers:
DF = the sticker on the D face.
FD = the sticker on the F face.
Same piece, different stickers — order matters.

The same rule extends to corners: URF is the U-face sticker of corner URF; FUR is its F-face sticker.