nuintari's rules of networking 0x5f:
Never start a hostname with anything other than an alphabetic character. There is a significant amount of software that cannot deal with labels starting with anything else.
-------Commentary-------
In the network I am unfucking, I have to document devices named 1foo and 2bar as onefoo and twobar, because the software I am using to generate graphs(graphviz) shits on nodes starting with a numeric.