Commands: Two, the first of which is: "Files, file to the right (or left)." The second of which is: "File leaders, lead up your files as you were to this ground." After soldiers have sufficiently drilled for proceeding a file at a time, they may expand their repertoire by understanding this command: "Files, file to the right." It means one file at a time, beginning with the right-most file, proceeds forward and then without further commands the next file falls in behind, and so on.  Of course they need to be informed where to stop and whether or not to resume their former order at that place.  The animation above has the soldiers resuming their former order; if the officer or sergeant wishes them to remain in one file, the command could be as: "Maintain one file and march on." Sergeant Subtlelus says: If the officer or sergeant is feeling adventurous, he could make one file from BOTH sides with the command: "Files, file to the right AND LEFT."  After the right-most file has moved and is clear, the left-most file falls in behind it, then the second right-most file falls in behind that one, and so on, narrowing the unit down on both sides, alternating from side to side.  This is one way to bring musketeers who had been sleeves on both sides of the unit into one division at the front, with the pike, who had constituted the center, becoming the second and following division.