So yesterday I was trying to sell freshly looted Snowman Packages (not used!) by using option "trade with". After several tries of making a trade- It was still remaining in my backpack. The other player and I were considering there is an issue with the Cap - but we both seemed to be ok with that too. Finally, I took a risk and handed the item on depot, and as person paid to be without any issues I doubt he lied to me.
Now, I obviously regret to getting rid of all Snowman Package to taste it further (perhaps bug? or other person has lied to me?) but this brings me to question:
What are all instances (cap, rejection, distance etc etc) or what items I will not be able to use "trade with" option.