Fall leaf pickup...or not.

"It’s time for the City’s Annual Fall Leaf Clean-up!

Residents can fill specially marked leaf bags with fallen leaves and place them curbside for free pickup service by City of Montrose public works crews. No need to call for special pickup. Residents are advised to utilize this free service, and to not rake fallen leaves into street gutters. Crews will pick up leaf bags until mid-December. This free leaf pickup service is available to all City of Montrose utility customers. "

"specially marked leaf bags" what exactly does this mean?

I bagged my leaves in the normal black plastic leaf bags and there they sit at the end of my yard, as do a lot of lonely black plastic leaf bags looking for a new home.  Why do they sit, well it seems you have to use clear plastic yard bags, hmmm, is that what "specially marked leaf bags" is referring too?  I am not sure it is most vague.  Please, City of Montrose, be more consise with the information on your website.......and please come get these leaf bags, I promise I am not hiding trash in those mysterious black plastic bags.