linux - hostname Upper Or Lowercase ?

What is the general feeling for the case of hostnames in Linux/UNIX, is it preferable to have them in lower-case or upper-case? I have always preferred them as lower-case but I am interested to see if there are any arguments for or against this practice.

Host names are case insensitive.

Lower case has been the standard usage ever since there has been domain name servers.

source - http://forums.fedoraforum.org/showthread.php?t=268929