Here is one command I like to use A LOT from Cookes Manual

MOVEMENTS BY FOURS, THE PLATOON BEING IN COLUMN OR IN LINE.

283 The platoon being in line, to form it in a column of fours, the instructor commands:

1.       Fours, right, (or left

2.       MARCH.

3.       HALT.

At the command, MARCH, each set of fours executes its wheel of a quarter of a circle, on the principles prescribed for the wheel on the fixed pivot; Nos 1 or Nos. 4 turn upon the fore feet of their horses gradually, keeping square with the other flank: the others preserve their intervals from the pivot, and also regulate their alignment by the marching flank. At the command, HALT, the troopers straighten their horses and halt. If the command, HALT, is omitted, they move off straight in the new direction at the gait of the marching flank.

284 The platoon, marching in column of fours, to march it in line to a flank, the instructor commands:

1.       FoursRIGHT, (or Foursleft.)

2.       Guide left (or right)

At the first command, the pivots halt, and the wheels are executed on the same principle, (No. 283,) and at the mo­ment of their completion all move forward in line.

So what does all that mean?

If we are in a line this is what should happen when I give the command FOURS RIGHT- MARCH

                                                                                             4              4

                                                                                             3               3       

                                                                                             2              2     

                       4     3     2     1     4      3     2      1                 1               1

                         Starting Positions                                  Ending Positions

You will notice the ONES pivot where they stand to face to their right. Each set of four pivots to its right, anchored on the ONES

Now if we are in a column of fours and I give the command of  FOURS LEFT-MARCH

                  4                   4

                 3                    3          

                 2                    2

                1                    1                   4    3     2     1      4     3      2     1

       Starting   Positions                   Ending  Positions   

 We should end up with a line facing what had been our left. This time the FOURS anchor our sets of fours pivot.

REMEMBER ---- WHEN I GIVE THE COMMAND FOURS RIGHT(OR LEFT)- MARCH.

 THE PIVOT STOPS AND PIVOTS ON THE SPOT WHEN YOU HEAR THE WORD MARCH !