khartoum, sudan -- If you are in Sudan, it is a "missed call." In Ethiopia, it is a "miskin" or a "pitiful" call. In other parts of Africa, it is a case of "flashing," "beeping" or in French-speaking areas, "bipage."
Wherever you are, it is one of the fastest-growing phenomena in the continent's booming mobile phone markets -- and it's a headache for cell system owners who are trying to figure out how to make some money out of it.
You beep someone when you call them up on their mobile phone -- setting its display screen briefly flashing -- then hang up half a second later, before they have had a chance to answer. Your friend, you hope, sees your name and number on the "missed calls" list and calls you back at his or her expense.
It is a tactic born out of ingenuity and necessity, say analysts who have tracked an explosion in miskin calls by cash-strapped cellphone users from Cape Town to Cairo.
"Its roots are as a strategy to save money," said Jonathan Donner, a researcher for Microsoft Corp. who has a paper, "The Rules of Beeping," in this month's online Journal of Computer Mediated Communication.
Unlike U.S. carriers, which split the cost of a mobile call between the caller and the person being called, most carriers elsewhere in the world place the entire cost of a mobile call on the caller, so receiving calls is free.
Donner first came across beeping in Rwanda, then tracked it across the continent and beyond, to South and Southeast Asia. Studies quoted in his paper estimate that 20% to more than 30% of the calls made in Africa were just split-second flashes -- empty appeals across the cellular network.
The beeping boom is growing with the sharp rise in mobile phone use across the continent.
Africa had an estimated 192.5 million mobile phone users in 2006, up from just 25.3 million in 2001, according to figures from the U.N. International Telecommunication Union. Customers may have enough money for the purchase of a handset but very little ready cash to spend on phone cards for the prepaid accounts that dominate the market.
Africa's mobile phone companies say the practice has become so widespread they have had to step in to prevent their circuits from being swamped by second-long calls.
Beeping is not only about money. Donner's "Rules of Beeping" suggests a social protocol for the practice.
"The richer guy pays," he writes.
Some of his rules: It is acceptable to beep someone if you are short of cash and they are flush with credit. Never beep someone poorer than you. Never beep someone you are tapping for a favor; you don't want to risk annoying the person you are trying to win over. Never beep your girlfriend, unless you want to look cheap.
"Most beeps are requests to the mobile owner to call back immediately, but can also send a pre-negotiated instrumental message such as 'Pick me up now,' or send a relational sign, such as "I'm thinking of you,' " the paper says.
It can go even further than that. Cameroonian researchers Victor W.A. Mbarika and Irene Mbarika identified a different kind of beeping-powered relational call in a study for the Institute of Electrical and Electronics Engineers.
"Lovers often communicate with text messages or 'beeping,' " said the study. "One party dials another's number and then hangs up. One ring could mean, 'I am here,' two rings, 'Call me now.' "
And the name they gave this new entry in the beeping lexicon? "Booty call."