can anyone help me decipher this??

Those are L-numbers for plecostomus. The fish most of us refer to as a pleco is actually a Loricariidae (spelling varies--this is what Fish Base and Planet Catfish use). There are new species/types imported frequently. Until the fish can be postively identified and named, it is given a numeric designation, preceded by the L to identify the family. Sometimes, the fish is assigned multiple L-designations, because it was imported 2-3 times with slight variations of color, size, or genders. Once the critter is ID'd, it's given a name, and usually the L# sticks with it to help hobbyists who acquired the fish prior to it's official recognition.

Plant Catfish is one of the best places to go for help with L#'s. They list the fishes both ways. http://www.planetcatfish.com/core/index.htm

HTH