WHEN the Saudi employer of a Filipina domestic helper refused to let her return home after her contract was finished, friends sent a single text message that simultaneously alerted authorities in the Philippines and agencies helping migrant workers in distress in the desert kingdom.
It was received by a mobile phone linked to a computer server in the Manila appartment of IT expert Bobby Soriano. The server, bought from a junk shop, immediately routed the text message to the groups that may be able to help her.
"When the SMS (short message service) is sent the system sends back an automatic reply that it has been received and that somebody will call them," said Mr Soriano, who helped developed the system for the Centre for Migrant Advocacy, a local NGO.
Between six and 10 SOS SMS' a day are received a day, said Mr Soriano. Over half are from Saudi Arabia, where 1.4 million Filipinos work, mostly on short-term contracts.
It should be better known. The simple but effective system, for one, is particularly suited to this nation of avid texters.
SMS traffic in the Philippines is one of the heaviest in the world, reportedly exceeding voice calls by 10 to 1.
And practically all Filipino overseas workers own a mobile phone.
Many of the texts for help are from Filipinos complaining that their wages have not been paid or that they are working in dire conditions, said Mr Soriano.
Others, mainly domestic helpers, want rescuing from physical and sexual abusive at the hands of their employers. There have even been messages from seafarers stranded in far-off ports and Filipinos fleeing war zones.
The beauty of SOS SMS' is that they are directly routed to the Philippine government's welfare agency for overseas workers and the Department of Foreign Affairs.
In the case of the domestic helper in Saudi Arabia, Philippine embassy officials there went to her employer's home in the northern city of Gurayat and took her into their care.
"I had a contract for two years but I stayed for four and received no salary for the last 18 months," said the 26-year-old, whose first name is Rubelyn. She was flown home and is now back with her family in the southern port city of Davao.
Ninety-six Filipinos working in a glass-making factory near the Polish city of Lodz sent an SOS SMS on April 9. Like many, it started with a touchingly polite greeting: "Gud pm Sr/Mam we want to seek your help..."
They complained that they were not paid the agreed salary and that working conditions were bad. Some reportedly stayed in a church and relied on food donations after being fired. Philippine officials flew to Poland to organise their repatriation and the first batch of 49 arrived back home on May 7.
Some 2,00 Filipinos overseas workers in distress were repatriated in 2008.
The cost of an SMS SOS is around a peso - about 3 Singapore cents - using a local phone plan with a roaming facility, which most Filipinos working overseas use.
The SOS SMS number is:+63 920 9639 767.