Package Prefix page in project properties - is there a way to add or remove items?

[patluze]

Nice work on this project - thanks!

I can use the Edit button on the Package Prefix page in project properties after I add some prefixes by adding a prefixes.properties file to my Eclipse project, but I don't see a way to add or remove items via the Package Prefix page. Is there a way to add/remove items? My apology in advance if I missed something obvious.