If you are wondering how to properly discard pizza boxes, here is the answer from RecycleSmartMA.org: put these items into recycling bins.

EMPTY pizza boxes can be recycled (with the exception of frozen pizza boxes). Grease is OK.
Remove all food, liners, and pizza savers (plastic tables) before putting the box in the recycling. Leftover pizza can be composted or put in the trash. Liners and pizza savers go in the trash.
Pro tip: Fold the box inside out before putting it in the recycling. This will ensure the box is completely empty so there are no surprises at the sorting facility.
What about grease?
Grease is OK! Paper recycling mills have assured us that it does not interfere with the paper-making process. For more information, check out this newsletter “No Matter How You Slice It.”
Please check the "Can I Recycle This?" page at Recyclopedia for any question you might have.
Thank you for recycling at Burns Manor Condo.
Thank you for recycling at Burns Manor Condo.