[chaley]

Originally Posted by Ma'am-I-Am

OK, I searched and OMG this makes my head hurt and my eyes cross. So I'm just gonna ask.
When I know a book is retail, I tag it "Retail" or "Retail EPUB", etc.. Foolishly, I have tons of duplicate books - some retail, some not.
I want to create a column which will search each book's tags and - if certain tags are found, such as "Retail" - will populate that column with that found tag.
The goal is to quickly compare duplicate books to see which version is retail.

Can anyone help? If you have a better way to achieve my goal, say so!

Approach 1: a custom column with a template. I can understand that idea making your head hurt. You might want to look at Approach 2 below first.

Custom column:
Steps:

1. Create a new "Column built from other columns, behaves like tags". Name it whatever you want.
2. Use this as the template.
   

   program:
   	list_intersection($tags, 'Retail, Retail EPUB, whatever', ',')

3. Ensure that the string 'Retail, Retail EPUB, whatever' contains all the tags of interest. Each tag is separated by a comma. Spelling must be exact, but letter case doesn't matter.

The new column will show the tags from the list that are in the book.

Approach 2: use a column icon to mark books with any of the tags of interest. This image shows what it might look like using a downloaded icon on the title column.



Steps to do this:

1. Find an icon you want to use. Easiest is an online search. The icon should be square, 128x128 pixels (a bit bigger is OK). One icon site is https://www.iconfinder.com/.
2. Download the icon to a place you can easily find it. I usually use my desktop.
3. In calibre, go to Preferences / Look & feel / Column icons.
4. Click the Add rule button.
5. Use the "Add icon" button to add the downloaded icon to calibre.
6. For the rest of the dialog:
   • "Set the:" box: icon with text
   • "of the column:" box: Title (or whichever column you want)
   • "To:" the icon you downloaded
   • Only if the following conditions are all satisfied:
     • Choose "Tags" for first box: "If the ...
     • Choose "has" for the second box.
     • Enter the list of tags of interest into the third box, for example "Retail, Retail EPUB", separated by commas. Again, the spelling must be exact but letter case doesn't matter.
     • Press OK, then Apply.
     My example dialog looks like this: