Q: I was considering buying a co-op on the Upper East Side with a private back yard that was included in the offering plan. The seller and I agreed on the price, but then the co-op board introduced a licensing agreement that imposed a monthly charge equal to 18 shares to use the yard — though the buyer would not get those shares. The board also imposed rules regarding how and when the back yard could be used. Potential buyers had to sign the agreement to be considered. Is it legal for a co-op board to impose a separate fee for an amenity that belongs to the unit?   Read the Q&A………………………………..