Originally Posted by dwanthny
I don't know why a + is being added as a tag, but when creating a catalog in calibre I believe every book that has a + as a tag treated as read.
Yep - did a lot of Googling, to confirm this.
I'm sure that the + is added by "Fetch Annotations", no matter which custom columns you might have had.
I would guess the idea was to Mark a book "read" by adding the + to the tags. This was way before custom columns etc.
Not sure what value for inserting the + is