Apply 'ad tag' to ads in specific categories automatically
I've recently bought ClassiPress - loving it so far and have successfully been building out a free trading site for my niche.
I've also bought a couple of additional plugins, one being the 'ribbons' plugin.
With the ribbon plugin you are required to add an ad tag to its settings area so it knows to apply the 'used' ribbon to a post.
However I don't want my users to have to enter a tag when completing their ads just so that this ribbon is applied. Theres only 1 tag I want to be applied to posts.
Basically I have a 'Want to buy' category with subcategories. I want an ad tag applied automatically to ads that are posted in any of these categories.
I'd really appreciate some help on this, I've been search around, found some 3rd part plugins etc with no luck.
I've setup a child theme with its own functions file and am prepared to manually add the code I just need some guidance