How to create an RSS "dynamic" Item with prefixed Parent Item/Category

Wondering if anyone can advise or direct me to technical resources/examples for how to go about creating or suggesting to a site owner how to create an RSS feed "dynamic Item" which includes the item's immediate parent item/category.

Example:
I subscribe to an RSS feed for discussions on a website which hosts multiple discussion forums. I belong to both a Red Forum and Blue forum with various, new and different discussions being started all the time in each. I review new/updated RSS subscription items in a web-based RSS Reader like Google Reader. Today I might see 2 new/updated ITEM subject lines like "Discussion ABC" and "Discussion XYZ". I have no context to know in which forum either of those discussion subject lines belong. What I'd like to have shown for the new/updated RSS ITEM subject lines are : "Red forum - Discussion XYZ" and "Blue forum - Discussion ABC"

Hope that example describes the objective clearly.
Thanks in advance for your consideration of this request.