Flank files

the first men on the right, and the last on the left, of a company, battalion, etc.

See also: Flank

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
``Able Company has planned to wade ashore in three files from each boat,center file going first, then flank files peeling off to right and left.