Board Thread:New Features/@comment-2240397-20161117122547/@comment-1370845-20161125123807

That seems best to me. The ability to add more than one theme to  and separate via | or ; seems best. It may be preferable to set it to ; though, since if  is supposed to be able to add multiple themes, then separating the new theme out by | will make it think it's a new template parameter.