This is a reference to PR shoes — Puerto Rican shoes — he was wearing what was popular in the height of Harlem for a smack dealer circa 1968. “P.R. shoes” are the type of zapatos associated with hip uptown Puerto Ricans at that time: shiny leather with pointed toe
Lou Reed noted in his book of collected lyrics “Between Thought And Expression” that what’s meant here is “Puerto Rican Fence Climbers”. Which makes sense for a man who may have to make a swift getaway at any time, the ability to climb fences on the run is extremely necessary.
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