vim :ch-ch-ch-changes

Tip #1300 over at vim.org (you do know about vim tips, right?) is very handy:

Some times I wonder what was changed in the file currently opend. By accident I came across the “:changes” command. This command prints all changes in the file. With “g;” you can step back to the previouse change in the list, typing “g,” you step to the next change.

Type “:help changes” for more information.