I noted that some edits create new revision of the answer\question, and some just modifies the last revision (merged with previous edits).
What does it depend on? Since I've been asked to keep revision history of my answers to minimum, i would like to predict this behaviour. What are exact conditions for each of this results?
Edits within a grace period of the first five minutes of a post's creation or the last edit do not appear in the revision history.
Since I've been asked to keep revision history of my answers to minimum
A better way of doing this is simply to not edit tiny things as you see them, which can also be annoying in that the "this post has been edited" banner keeps showing up.
Instead, when you want to edit your post, look for all the improvements you can make before you click "submit"! That way, instead of having 10 tiny edits in a row, they can all become 1 major edit.
Sidenote: please don't hesitate to improve a post just because it will add another revision. With the removal of auto-CW, it's now just purely aesthetic. Avoid cluttering the history by making your edits major enough to correct all the problems in the post, but don't worry about adding a revision, as long as you're trying to make the post better!
