Currently there are only 2 options for reporting errors, "Typo/spelling/grammar" and "Disputing Answer".
Often there are other reasons for suggesting improvements e.g. the ii is out of date, the question is misleading or badly phrased etc etc
A third option "Other" would cover everything else which isn't currently covered by the existing 2 options.

As an editor, I never even look to see that, I just read the message and decide how to act on it. As a player, I use the first option for all kinds of errors that are not related to the accuracy of the answer.

But the correction system should not be used for suggesting improvements. If it is out of date, that is an error, as is a misleading question. If it is just badly phrased, or could be better (or, which we see more often, could have more information), that is not something for the correction system. Those suggestions are better sent to the author by a personal message. (Every correction has to be reviewed by an editor, so suggestions for improvement that would be nice but not essential just clog up the system.)

If it is badly phrased to the point of being misleading or difficult to understand, I would certainly accept a correction note on that.

I want to second l_t's point - don't worry about which of those boxes you tick. They all go to the same place, and to be honest, I'm not entirely sure it's even visible.....I've certainly never paid any attention to it.

Thanks for the responses - I won't worry about which box to tick in future.