Tree tags

   I have been thinking to write about trees with these tags on them for a while. I see them regularly in Golden Gate Park, and my level of interest in exploring them further has oscillated between pretty interested to not-that-interested. Perhaps this lack of fascination has led to me not exploring the question further, and I'm happy with that at this moment.
   I have experienced that knowledge of a thing can rob it of its' mystery for me, and while I very much enjoy information, I find what I don't know to be much more intriguing; it leads me to ponder, and as long as I don't do so too intensely, there is a mystery and beauty in that space between familiarity and enigma.
   I couldn't with good conscience begin writing this blog entry today, after having the idea to write about it more than a month ago, without at least trying to find some information on it. I searched the internet a bit, but could not find the information I was looking for on these things (seen in the picture below), so I just went ahead and began writing on the subject anyway. If I made myself a reminder to ask someone at the park tomorrow about them, I could probably find out what these numbers meant, stamped on what looks like tin and then hammered onto the base of certain trees.
   Instead, I'll just finish writing about them here, publishing it before I have the chance to know differently or why.
   I keep looking for one that will have my birth year on it, as most seem to begin with the numbers "19" on them, but have yet to find it. The one below appears to be the closest so far.