One of your best clients - who happens to be haredi - has just told you he likes your heimish approach to doing business. But all you can do is smile stupidly because you have no idea what he said. Such social blunders are ill-afforded with haredi buying power on the rise. Although no data is available on exactly how much the sector spends, rough estimates set the haredi population at about 700,000, most of whom are under the age of 18. According to the Central Bureau of Statistics, by 2009 one out of every two babies born in Israel will be either Arab or haredi. In an attempt to bridge the cultural gulf between the secular business sector and the haredi clientele they serve, Trio, an advertising agency that specializes in the haredi, Russian and Arab consumer markets, has in recent days e-mailed a lexicon of common haredi terms to its clients. Marketers at Hertz car rentals, Israel Electric Company, Proctor and Gamble, Super-Sol and Mizrahi Bank's Tefahot Mortgages were all given a crash course in lingua haredi. Chulent (meat stew), streimel (a hat preferred by Hassidim made of Siberian fox tails) viseh zaken (the long white socks worn by some Hassidic sects) and kishke (stuffed intestines) are just some of the terms - mostly Yiddish - included in the lexicon. "It's just another variation on multi-cultural marketing," said Trio CEO Gadi Margolit, who said he manages an annual haredi advertising budget of about NIS 15 million. Yigal Revach, CEO of Afikim, one of the leading advertising agencies serving the haredi market with an annual budget of more than NIS 30 million, said his company published a similar lexicon a year ago. "We try to help our clients better understand behavior that is unique to the haredi sector," said Revach. "For instance, a door-to-door salesman might be offended if he confronts a haredi woman alone in the house who insists on keeping her door wide open. He does not realize that Jewish law forbids a woman to be alone in a closed room with a man who is not her husband." Haredi buying power has come to the fore most recently in the ongoing struggle with El Al. Haredim, who are some of El Al's most important and faithful clients, are threatening to completely boycott the national carrier unless it signs a legally binding contract - complete with a hefty fine - that it will not fly on Shabbat without rabbinic consent. Haredi consumers have flexed their market muscles in the past to obtain exclusive real estate projects, "kosher" electricity and food that meets the most stringent halachic requirements. Though nominally of the same religion and belonging to the same people, secular and haredi Israelis often have radically different cultural affiliations and social codes. However, market forces and the pursuit of profits appear to be a unifying force where politics and social processes have tended to divide in the past. Trio, Afikim and other advertising agencies educate their clients in the intricate cultural sensibilities of this fast-growing, influential market thus fostering better understanding, albeit for the purpose of earning a buck. Trio's lexicon is a tool in this education process. The lexicon splits up haredi jargon into different spheres of lifestyle. For instance, vort (cementing the matchmaking) and tna'im (finalizing the monetary conditions for the marriage) are both important terms that should be understood by mortgage bankers since the purchase of a flat is normally part of any marriage agreement in the haredi sector. Media terms such as nayes (news), mikve nayes (news or gossip told in males' ritual bathhouses) and pashkevilim (the black and white notices plastered on the walls and bulletin boards of haredi neighborhoods, often written in a fire and brimstone style) are important for every marketer interested in using below-the-line marketing techniques. Alas (which stands for an area without movies [ezor lelo sratim] on a plane and also implies segregated seating for men and women) is an important term for travel agents and stewardesses to know. Other terms include mizrach (the place of honor at a wedding or other celebration), shtibalach (a collection of synagogues where one can easily find a prayer quorum), koylish (a long, festive loaf of bread), kapota (a long robe), castum (a custom-made wig for women) and yeshar ko'ach (an expression of thanks or appreciation for a good deed).