What is this?

Or rather, what is the significance of this:

Wall Graffiti at a transmitter site
Wall graffiti at a transmitter site

A few hints; it was found (written on a wall) of an old, mountain top transmitter site. We are renovating this site and it was underneath an old  old alarm panel from the 1970’s that I removed. It reads 468 ÷ 45 = 10.   and the 468 is significant.

Once upon a time, a person could go to the TELCO demark and get all of the inside numbers for the CO and any number of CO’s in the area.  They would be scribbled on the wall next to the equipment along with many other numbers.   This was especially helpful when doing emergency trouble shooting on a circuit that was down.  Try to do that these days and the most likely result is an unanswered phone.  Most of the smaller CO’s are not normally manned unless there is a trouble ticket in process.