Here's an example: https://mappingsupport.com/p/gmap4.php?ll=38.025076,-119.421796&z=15&t=t4&markers=||38.018311,-119.419928^^<span%20style='font-weight:bold;font-size:1.2em;'>38.018311,-119.419928</span>
At first I thought it was some sort of benchmark - but seeing where they are located (apparently at random in the physical world) it appears that they may be some type of alignment marks for the mapping/map-making process. Google was not my friend with this one. Any ideas?