My suggestion is simple, as you know in /stats you are able to see the group you are in and your rank. Show content
(http://i.imgur.com/Ui9p3Kf.jpg)
As a result I think adding something like "Squad Rank:(your squad rank)" under "Squad:" would be useful to people who wish to join a squad and they are told to message for example deputy for an invite but they can't see their rank. Also this allows people to keep up with what rank they are in their squad.
However, a drawback of this suggestion is that squads aren't as popular as groups.