Alternate version of lol or "hahaha" in online or text conversation, usually with someone who speaks Thai. The Thai word for 5 is pronounced "ha", so three of them would be pronounced "hahaha"
Guy texting woman in Thailand: Did you go to the doctor and get that rash on your cooch checked out?
Bar girl reply: Yes, docter say boom boom now, ok.
Guy's reply: Come over then. And don't forget your sister, 555.
Numbers used in movies, television, magazines . . ect. as the first three characters in a phone number so as not to promote stalkers who would otherwiseactually call that number.