A FRENCHMAN ordering un hotdog is on safe linguistic ground, even if he risks commiting culinary heresy. But suppose he has a date. Suppose again that he has to submit his order in writing. Make that deux hotdog? Or deux hotdogs?

A government-appointed commission has come to the nation's rescue by providing an answer (the plural of hotdog in French is now hotdogs) to this and other burning dilemmas in the spelling and usage of French.

Such matters are not taken lightly in France, where facility in language is a matter of honor, pride and ultimately national identity. Last October, Prime Minister Michel Rocard appointed a working group in the Academie Francaise, the guardian of standards for French literature and language, to deal with five common problems in spelling.

The pluralization of foreign phrases (deux raviolis, deux weekends, etc.) that have found their way into frequent French usage was one such problem; others were the use of accent marks and the circumflex, the use of hyphens (pique-nique has become piquenique) and a couple of even more exotic items.

The working group reported back to Rocard on June 19 with its recommendations that affect the spelling of some 1200 words, and the prime minister interrupted his fight on inflation, his effort to find money for the French nuclear deterrent and other weighty matters to accept the recommendations in the name of the French nation. French newspapers devoted lengthy articles to the changes and pointedly noted the Academie's "recommendation" to teachers, journalists and all others who deal with the written word to promulgate the changes.

France is a country where the national spelling bee is conducted on prime time television and brings signficant monetary rewards to the winner. The function of a public school system formed out of the Revolution of 1789 is first of all to teach the speaking and writing of the French language. This, many historians believe, was the crucial first step toward forming the modern French nation out of the diverse linguistic and cultural groups that inhabited France before the Revolution.

British diplomat Harold Nicholson believed that speaking and thinking this rigorously formed and policed language has given the French a competitive advantage in government and diplomacy. It is impossible to speak French correctly unless you have organized what you want to say in a logical and coherent fashion, Nicholson maintained.

But the increasing penetration of French by English, German and other foreign words has made "defending or reforming of spelling a national psychodrama," the newspaper Liberation noted in its report, which congratulated the Academie for having come up with its recommendations in only a little more than six months.

De Gaulle's best known quip about France was that it was impossible to govern any country that then made 265 different kinds of cheese (it now makes 326 cheeses). But his joke hid the more important truth: that it is a country with one set of rules and standards, defined by its sages and enforced through its control of the language. This is a strong line of defense in the identity battle France is now waging.