The questioner cannot use E-Prime because he doesn't know what E-Prime is. And before being interested in its description, he'll probably want to know what it i

The questioner cannot use E-Prime because he doesn't know what E-Prime is. And before being interested in its description, he'll probably want to know what it is (is it a law? is it a game? is it a style guide? a brain training exercise? is it a dog?). See, "E-Prime" is a proper noun, and proper nouns don't have a meaning; they instead refer to specific things (giving them an identity). The same way Spain is a country, E-Prime is "a variant of English."