WordPress automatically keeps a copy of each modification you do to a post. This allows you to go back in history and restore revisions in case you did something wrong, or just because you want to recover something that was overwritten for any reason.
For sites hosted with us, we limit the number of revisions kept for every post to a maximum of 500. We are taking this action to ensure sites performance are not harmed by the unnecessary amount of revisions we are currently keeping.
Revisions are backup copies of each modified version a post or page has. It allows you to see the history of every modification made to a post and to restore a previous version of it.
In average, a regular post has way less than 500 revisions and this limit affects only a small number of posts and sites.
Major revisions
If you have an important revision you want to keep, you can do so by marking it as a “Major revision”. These revisions will never be deleted, even if the 500 limit is reached. Here’s how to do it:
On your post’s sidebar, click on the number of revisions.
In the Revisions screen, use the slider at the top to browse the revisions and choose the one you want to mark as major.
Click on “Mark as a major revision”.
Major revisions are marked with a dot on the top of its position in the slider. You will also notice that the button label will change to “Unmark as a major revision”.
Note: For pages that make use of dynamic blocks, such as the Homepage blocks, in which you define the criteria of the posts that will be displayed, what is saved in the revision is the position of the block and those criteria, not the posts that are being displayed in the block at that moment.