WPML

I'm trying to use the WPML plugin as it seems to be the most complete translation plugin for wordpress and the only one that integrates with buddypress.

In the setup it says:
Enter the theme's textdomain value:
(Theme localization is not enabled because you didn't enter a text-domain.)

I'm really not entirely sure what this from their documentation, but I believe it is a tag specified in a theme for the phrases that the plugin will translate.

Is there a list of the "Text Domain" for your themes?