Join A Clan - You Need To Be Corperal. I AM!

Hi,
Right my freind just made a CF Clan, so im nearly 2nd Lt, well like far off.
But, I went to join saying :
Im Pwnage, Let me Join The persons name.
It said.
In yellow:
You Need To Be Corperal Or Higher To Join A Clan.
Help Please..
Thanks.
//iDont.