Write tag with custom name

[Xerus]

Would it be possible to write a custom tag with a simple String identifier? There's already tag.getFields(String), but there is no pendant to it. I know that there are the CUSTOM 1-5 FieldKeys, but when the users view the tags they should get the idea of what it means, and CUSTOMX is not very telling.

Another idea would be to be able to manipulate the "name" of a custom Key, so that the tag has a more telling name?

[IJabz]

Yes this is indeed needed, actually an extension of Issue #8