What does LOOP mean on an oversize permit?

Loop. A loop road around or through a town, numbered like a highway: LOOP 256.

Also printed as LP.

On real permits

PrintedMeansState
SR 202 LoopLoop 202, State Route 202 around metro PhoenixArizona
SL256 sw [LOOP 256]State Loop 256, heading southwestTexas

Decode a whole route line