One of the Kindle's most desired features is the addition of tags, folders, and/or collections.
The Kindle does have a good search feature. It would be huge, if Calibre had an option to insert its tags in the first line of each mobi book it creates.
One problem is that the search feature would find every instance of a tag, even if it was just a word in the book. So, "empire" as a search term would select every instance of empire in every book. Instead, there would need to be some type of tag delimiter. Using this approach, if I search for:
...Empire... I would likely only find matches in the "tag area" inserted by Calibre.
I know that I need to add this as a ticket if I'm really interested in it. However, before I waste kovidgoyal's time, I thought I would air this out in this forum. I already sent him one "ticket" that I should have been able to research myself without bothering him
(thanks for the quick response, kovidgoyal).