Remove Duplicate Line in Vim?

Question

I\'m trying to use VIM to remove a duplicate line in an XML file I created. (I can\'t recreate the file because the ID numbers will change.)

The file looks something

Answer 1

A simple regular expression won't suffice. I've implemented a

:DeleteDuplicateLinesIgnoring

command (as well as related commands) in my PatternsOnText plugin. You can even supply a {pattern} to exclude certain lines from the de-duplication.