https://pe.usps.com/IMM_Archive/HTML/IMM_Archive_20120122/imm/immc1_014.htm
136 Nonmailable Goods
goods
https://reason.com/2015/12/18/marijuana-ads-are-nonmailable-but-that-d/
Marijuana Ads Are 'Nonmailable,' but That Doesn't Mean You Can't Mail Them
Dec 18, 2015 - The U.S. Postal Service simultaneously clarifies and muddies its policy on cannabis promotion.