Cards can be currently generated selectively based on a field being non-empty.
Sometimes you may want to generate extra cards for only some of your material, such as testing your ability to recall the most important words of a set. You can accomplish this by adding an extra field to your note, and adding some text into it (such as “1”) on the notes you want the extra card. Then in the card template, you can make the card’s creation depend on that field being non-empty.
— Card Generation - Anki Manual (ankiweb.net)
It would be nice to be able to do the same but using a tag instead of adding an extra field, e.g.
This text is always shown.
{{#Tag:production}}
This text is only shown if the card has a tag “production”.
{{/Tag:production}}
This would also allow changing card style through tags, although this is currently somewhat possible via Javascript or awkward css tricks such as <span class="{{Tags}}" />
.