Don't use this for backpacking
This shirt has an inside tag and a spare button right where your hipbelt goes. It also has a pocket that goes down to where the hipbelt goes so that if I put something in the pocket it would interfere with my hipbelt. Then there is a pocket in addition to the zip pocket (not mentioned in the specs) that has no velcro stuff or button to shut it. There is a cloth flap that closes it but I can see overtime that this pocket is gonna definitely just start hanging open and no longer lie flush with the shirt. My size is small. Not sure if larger sizes are the same.