In the attached image, which shows one subtemplate, you can see how we are building out a website. Is there a way to automatically assign a subtemplate to match all items in a menu or submenu (in this case, the menu named 'SL')?

Though in this case, the client can handle module assignments and template management, I think the requirement of iterative human administrative activity multiplies the possibility of errors, especially given the presence of possibly six subtemplates.

Is there some sort of 'all pages except...' or 'always select subitems' available for such matters? (And if not...consider this a feature request.)

I would probably approach this by loading a custom css file based on the menu item id.

So you would put a switch in the template that would load a file that looked like this:

templates/[your-template]/css/custom-$menuitemid.css

So it's certainly possible but not something we are interested in adding to our themes. You could just handle the same thing by using Joomla styles which is what that system was designed for.

If you want us to help create this for you we could do it under a two hour block of time.

Cheers

Lot's of interesting ideas in your answer. Thanks.

Yes certainly was

I learnt something

Cheers
Paul