What potentially real 555 telephone number does Hollywood continue to use in movies and television shows -- even though it's no longer on the list of reserved fake phone numbers?

Good news, tragically single geeksters: The next time you manage to get a phone number from a romantic prospect that begins with the dialing prefix 555, it's possible that the target of your affections isn't giving you a pop-culture-inspired brush-off. Possible, but not likely. That's because, contrary to what conventional wisdom and years of movie- and television-consumption may have taught you, not every U.S. telephone number beginning with 555 is fake. Just lots of them.

The North American Numbering Plan -- which has been the governing document for assigning and maintaining telephone numbers in the United States, Canada, Mexico, and various nearby countries since 1947 -- was amended in 1994 to formally reserve exactly 100 telephone numbers for fictional use. That is to say, any telephone number falling between 555-0100 and 555-0199 would never be placed in service, and instead be reserved for use in movies, television, and other mass media works of fiction. Thus, if someone you chat up hands you a 555 phone number outside that range, they may not be scamming you. That said, most active 555 numbers are used by businesses or service lines, so odds are you are still being duped, but it's not a dead certainty.

The need for "fiction-safe" phone numbers is fairly straightforward; if a phone number becomes an element of pop culture, a certain percentage of fans will be unable to resist dialing it to see who answers, creating a nuisance for whichever poor sap happens to share a number with a fictional character or organization. Tommy Tutone's famous "867-5309/Jenny" pop song has been the classic example of this phenomenon.

In fact, fiction-safe phone numbers predate the 555 rule. Until the early 1970s, AT&T kept a list of inactive but potentially "real" phone numbers that it shared with Hollywood, but by 1973, every possible seven-digit phone number was in use somewhere in the United States. Thus, from 1973 on, the 555 exchange became Ma Bell's recommended fake phone prefix. In 1994, further demand for additional phone numbers forced the reserved list down to just 100 phone numbers under the 555 exchange.

Still, one quasi-fictional 555 telephone number from outside the 0100 to 0199 range remains a prominent fixture in Hollywood productions, as it has some traditional significance that predates the existence of not only fake 555 numbers, but 10-digit phone numbers altogether.

WHAT POTENTIALLY REAL 555 TELEPHONE NUMBER DOES HOLLYWOOD CONTINUE TO USE IN MOVIES AND TV SHOWS, AND WHY?