In several posts, I found one single mistake which in some cases, was crucial to the meaning of the sentence (with commas, especially) or at least very irritating. While I tried to eliminate the mistake in an otherwise quite flawless post, I always got the message that edits below an extent of 6 characters weren't possible. I then had to cancel the edit and leave the mistake where it was. Of course, now that my reputation is sufficient to edit posts without reviewing, I could change at random 6 other characters and reedit them to their former state afterwards, but this would seem a strange workaround to me. I can change one single character in my own posts, so why isn't it possible with the other ones?
Addendum: I just found this post to be a duplicate of this question, save that in my opinion, this former question doesn't seem to have received a fully satisfactory answer. When I see an obvious single fault in a text, I don't think it is fussy to correct it in the first place, nor do I find it reasonable to conclude that I now have to draw my full attention to the whole of the post, regardless of my intentions or qualifications as to its special content, or field of expertise. As I understand it, this is always intended to be a collaborative effort where also small contributions count.
I have found another issue concerning this, as Takkats answer to the older question includes the remark that with a reputation of more than 1000 also edits minor than 6 characters were possible – from my experience, I can't confirm this so far.