Create Personal Genre Tags?

I'm using MP3tag v2.36a, running it under Windows XP Home Edition.

I'm wondering if there's a way to to add more names to the "Genre" drop down list. For example, I'd like to create a genre called "Christmas." That name doesn't appear on the list. I looked also for "Xmas" and "Holiday" but they are also missing in action.

Also, is there an option for sub-genres in any subsequent versions of MP3tag?

And what I'd really like to have would be a field in which you could have multiple tags, separated by a forward slash (or some other punctuation mark or symbol) and which would permit Boolean searches.

So, that field could have an entry that looked something like this:

Christmas / jazz / vocal / 1940s / 1947 / Dixieland

But I'm getting off track here, aren't I?

So, back to my original question: "Is there a way that I can add my own genre names to the "Genre" list?

Go to Tools > Options > Genres.

The listed genres reflect the discrete list of genres that are valid for V1 tags. In V1 tags each tag is coded by a number which in return gets inflated to text as you know it.
V2 tags do not know this restriction. You can enter, whatever you like.
You can even create a (user-defined) field for SUBGENRE - the only problem will be that most players do not support user-defined fields. And the standard list of fields has no subgenre.
So in the end it is not so much a problem of MP3tag but much more of the abilities of you target system.

Thanks for the help, guys!

Tools > Options > Genres is just what I was looking for.

I tried to create a Sub-Genre column, using View>Customize columns, and that seemed to work, i.e., the new "Sub-Genre" column now shows up in the column display. But when I click on a cell in that new column, so that I can enter some text like "Christmas, Instrumental," nothing happens.

Any ideas on how I can enter text into the fields in my new "Sub-Genre" column?

I don't expect my MP3 player to recognize my new column. I just want to be able to use it to sort my MP3s when I'm creating playlists.

You have to fill in the two properties "value" and "field".
"Value" describes what you see.
"Field" describes the field in which the data should be stored.

So in your case you want to see and store values in
%subgenre%
which means that you have to input %subgenre% in both, value and field.

Hey! That did the trick!

Many thanks, ohrenkino and stanman for being so patient and helpful.