'Open with' application names. Where to edit?

I want to edit the text that appears alongside the application icons in the 'Open with' submenu.

There seem to be 3 choices:

HKCR\Local Settings\Software\Microsoft\Windows\Shell\MuiCache

HKU\S-...\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache

HKU\S-..._Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache

Or are they the same?  And shouldn't there be somewhere a bit more central to the application?

Thanks for any help you can give :)

DD