If you haven't seen these yet, they're pretty common with regiments from what I've seen. Of course, there are lots more on the Teamspeak forums if you just search for rank icons.
Spoiler
http://addons.teamspeak.com/directory/skins/icon-packs/33-High-Qualitiy-Military-Rank-Icons.html
Spoiler
http://addons.teamspeak.com/directory/skins/icon-packs/25-Rank-Icon-s-(16x16-and-original-file-included).html