DetlevD has a vast collection of sample actions and he apparently stores them for reference purposes. So you do not have to use the same name.
Have a look at the FAQs
/t/967/1
An action group is created if you press Alt-5, which opens the first dialogue, then "New", enter a decent name e.g. "Test_2011#20110606.Thorrrr" (just kidding, something like "mp4 cleanup" would be nice.).
Press OK.
The following, second dialogue has also a New button. Press it and enter the first action that DetlevD developed for you.
Save this action by pressing OK.
Back in the second dialogue you should see your just created action.
Press the New button again and enter DetlevD's second action.
Save it and so on until you have the 6 actions in the second dialogue.
Finally close the second dialogue with OK
You list of actions should have increased by 1.
You may carry out that action group straight away or call it from the Actions button in the toolbar.