What is considered a new post

[1979Shocker]

What determines where I go in a thread when I click on the little icon to go to the first new post? Is it a completely new post or can it be a post that someone has edited.

The reason I was asking is because I clicked the icon to go to the first new post for the thread "Current AAC NET Rankings and Resumes" and it took me to the first post of the thread, which had been edited by Stickboy46, and not one of the new posts on the last page.

[Kung Wu]

I don't know if editing a thread would cause it to become the first new post. I wouldn't think so, but maybe.