You are correct, J. In French cuisine, vinaigrette (sauce à l'huile) is, in its basic form, oil, vinegar, salt, and pepper. It may be modified somewhat and still called vinaigrette, but the modifications are all additions, not substitutions. (See "Larousse Gastronomique" - with an intro by Auguste Escoffier - or, more recently, "The Sauce Bible" by David Paul Larousse, who is unrelated to the first author.)

The substitution of lemon for vinegar is common in Mediterranean cuisines. Ladolemono is the Greek version, and in the Muslim nations the lemon-based sauce predominates, maybe because there is no wine from which to make vinegar. Add some garlic and herbs, and you have Sicilian salmoriglio. Here in Florida, I like to use lime juice occasionally to give the sauce a more Caribbean flavor. Of course, these are not vinaigrettes!

"I don't know which is worse: ignorance or apathy. And, frankly, I don't care." - Anonymous