Inventory Drawers is a feature that was planned for release in 2013. The feature would have allowed users to store items in custom categories for easy navigation. Not much is known about this feature. It was announced to be in progress in October 2012.
An original iteration of this feature was meant to be released sometime during or around June, 2010. It was announced in an interview with Kyle Stewart, one of the game's earlier developers under Zynga. Clearly, that iteration never came to fruition as well. Developers referred to this earlier version of the project as "Closets" rather than "Inventory Drawers" like its later planned iteration.
Players would have been able to add items to the drawers, rename the drawers, remove items from the drawers, and purchase additional drawers for YoCash. VIP users would have received more free drawers than non-VIP users.