Wikipedia
Guard Mount
Guard mount may refer to two things: The first is the actual forming (mounting) of a military security group called the Guard; the second is the bugle call which was used to signal the formation of the group.
Usage examples of "guard mount".
That song was officially forbidden, and it was certainly not an appropriate choice for the guard mount about to take posts outside the Grand Senate chambers.
I saw her name-and vowed that I would win the guard mount that evening and again be posted at the post of honor before the Prophet’.
I saw her name-and vowed that I would win the guard mount that evening and again be posted at the post of honor before the Prophet's own apartments.