Yes, the proper reading of the WHOIS record is, "Reserved by IANA for use in private networks." As encyclo said, it is an unroutable IP address range, just like 192.168.x.x and 10.x.x.x (and several others), and is reserved for use inside a LAN, similar to the way that 127.x.x.x is reserved for 'loopback' within a single machine. These addresses cannot pass through routers; They are meant only for use inside LANs. The reason they are not routable is so that anyone and everyone can use these ranges for their private networks; If they were routable, there would be a massive number of "collisions" because so many LANs use them.
OK, so that was about five ways to say the same thing... :)
So, it appears that someone at your hosting company is navigating your site from inside their network.