It's usually just for spelling. And once in awhile to add an extra sentence onto the end. But normally I spend a long time pondering about what exactly to write so it's not something that happens often!
And I never put a reason. That is silly.
I edit my posts almost all the time (75-100% of posts) and almost always specify.
I edit my posts almost all the time (75%-100% of posts) but rarely specify.
I edit my posts fairly often (50-75% of posts) and almost always specify.
I edit my posts fairly often (50-75% of posts) and rarely specify.
I edit my posts sometimes (25-50% of posts) and almost always specify.
I edit my posts sometimes (25-50% of posts) and rarely specify.
I rarely, if ever, edit my posts (0-25% of posts) and almost always specify
I rarely, if ever, edit my posts (0-25% of posts) and rarely specify.