answered question
At my department it is different than in the military.  It is used to keep there from being any confusion in relaying information to radio communications. A-adam B-boy C-charles D-david E-edward F-frank G-george H-henry I-ida J-john K-king L-lincoln M-mary N-nora O-ocean P-paul Q-queen R-robert S-sam T-tom you-union V-victor W-william X-x-ray Y-young Z-zebra