I get those too. Well I haven't gotten one in years. I kept one of the ones I got in the past and put it on the top of my stuff in my checked luggage.

I also add a "proof of fare" notice from the SFMTA.

Ive been debating printing out a TSA claim for damaged luggage and putting it in too and attaching a post -it. "Do it yourself and save me the trouble".

Ah stopping at Metro. What a neat store.
Nom Maynards.