[chaley]

Ahh... Thanks.

You just pointed me at a bug. With today's implementation, you should not be allowed to put a comma into the tag. Calibre is getting very confused, because it now has a tag with a comma in the middle of it, but commas are supposed to separate one tag from another.

Now to work out how to fix that. Perhaps in the process I can give you some of what you want. I won't be doing multiple selection, but I might be able to do tag splitting. With that, copy & paste would get you 90% the way there.

Edit: bug fixed. You can now 'rename' a tag to multiple tags by providing a comma-separated list. All of the resulting tags are applied to the books with the original. With this facility, it is possible to add tags without renaming. For example, change 'Fiction' to 'Fiction,MyTag', and 'MyTag' will be applied to all books already having 'Fiction'.

I did not implement multiple tag selection, because the changes would be very complicated. Instead, select one tag, change it as needed, copy the result, and then select/paste the copied result into the others you want to change.