As a technical matter, NAA and VLQ mostly do the same thing behind the scenes (although they're evaluated slightly differently in edge cases) and the same applies to Spam and Rude/Offensive
I guess we just wanted to know how best to handle a gibberish post without giving the overworked mods even more stuff to do unless that's the best way to do it.
@DavidG doesn't really matter. If it looks spammy, spam-flag it. If it looks rude/abusive/offensive, use that flag. Otherwise use whichever VLQ/NAA you can hit first.
if it's a new user, it doesn't matter (and spam is plausible). If it's someone who has reasonable posts elsewhere, then that spam flag will be declined because it'd mess them up for what was probably an innocent mistake.
Trivia: at one point, spam/offensive were the only flags in the system, so we used them for everything (also, there was no concept of a declined flag). The other flag types were added mostly for the benefit of the flaggers.
