RAS syndrome (short for "redundant acronym syndrome syndrome") refers to the use of one or more of the words that make up an acronym in conjunction with the abbreviated form, thus in effect repeating one or more words. Two common examples are "PIN number" (the "N" in PIN stands for "number") and "ATM machine" (the "M" in ATM stands for "machine"). Other names for the phenomenon include PNS syndrome ("PIN number syndrome syndrome", which expands to "personal identification number number syndrome syndrome") or RAP phrases ("redundant acronym phrase phrases").