So I took the time to learn how to post images.... :-)
Here is the postcard I referred to in a previous post...note the Pelican Bay State Prison Stamp, which indicates it has been inspected for gang codes, topics, etc. and approved for mailing. Every surface of every letter, postcard, picture or other items has this PBSP stamp. Also note the time/date stamp.
I explained in an earlier post that I am transcribing Bryan's letters because they are difficult to read as they don't scan well due to his small writing on both sides of the paper. Here is a sample of his writing.