from Wikipedia on Attorney general, commenting on one of my pet peeves:
Some people think the word "general" used in that way entitles the official to the honorific "general", but this is strictly only appropriate for military generals. The word "general" in "attorney general" is an adjective modifying "attorney". However, in the Supreme Court of the United States, the Attorney General of the United States and Solicitor General of the United States (for which office the same rule applies) are addressed as "General" by the Chief Justice. The plural of "attorney general" is "attorneys general." The history of the term dates back to Norman England when many of the French legal terms were imported into English common law. In French, the adjective often comes after the noun and so Attorney General meant General Attorney.
It's maddening that so many people insist on treating this as a rank like in the military, just because the word adjective "general is used". It makes no sense to address the U.S. Attorney General as General Holder, for example, given that he isn't being said to be a general of the U.S. attorneys but rather simply to be the U.S. attorney responsible for the government in general. You'd think the plural form "attorneys general" would signal to people that the word "general" is an adjective here.
But I think this is one of many cases where people are trying so hard to do something they see as correct but largely unrecognized that they end up being incorrect. (Another example would be those who use expressions like "Phil and I" as the object of a sentence after being told that you don't say "me and Phil", not realizing that it's only in a subject that you don't say "me and Phil" and that it's actually correct to say "me and Phil" in standard English.)