Thank you
I have been able to collect so many with a combination of traveling to the stores myself, others helping me, and trading tags with others for tags I didn't have. I have been lucky to find kindness among strangers.
Your list does not include Houston
Confirmed tags I don't have yet are:
Beijing, Shanghai, Taipei, Tokyo
Rumored, but never confirmed sightings are:
Miami (1 person mentioned/nobody has seen it)
Seattle (1 person mentioned/nobody has seen it. I have asked the stores in/around Seattle and they don't have it)
*You listed Pittsburgh but I have not seen this one. Being that there is a stamp for Philadelphia, I am wondering if there is confusion about Pittsburgh having one?