It's like the military then. The fact that there is a 101st airborne division does not imply the existence of 100 other airborne divisions.

Airborne divisions were originally just seen as specialized infantry divisions. They were numbered in sequence with all other infantry divisions. Thus, its number does imply the existence of 100 other infantry divisions.

Perhaps Seal Team 6 is a better example then? AFAIK, the 6 was a misinformation technique.

Edit: Haha, went and checked. Damn the lying documentary I watched.

What do you mean? Wikipedia agrees that 6 was disinformation.

https://en.m.wikipedia.org/wiki/SEAL_Team_Six

wrong comparison, military uses pay grades e1-9 for enlisted and o1-9 for officers, it is continuous.

So you can have a pay grade of o-pi or e-sqrt(2), although that would be quite irrational.

I believe that there WERE 100 other airborne divisions in the past, they just do not exist anymore. World War II required a lot of divisions airborne or otherwise.

No. Divisions 1-25 were regular Army, 26-50 were National Guard, and 51-108 were draftees. They were not designated according to MOS. Some of the divisions were never actually populated, so there are gaps even within this.

Later on, existing divisions were designated according to type. Infantry is the 'default' designation. Cavalry units were designated, then Armor, then Airborne, and finally Mountain. I have no idea when Artillery got its own designation. Some units subsequently were designated Air Assault, and this includes the 101st, but it kept the Airborne title to honor the unit history.

Other branches have other policies, but this is how the Army structure evolved.

The military explicitly does not number their units in numeric order as a counter intelligence measure.

In the book 'Surprise, Kill, Vanish: The Secret History of CIA Paramilitary Armies, Operators, and Assassins' by Annie Jacobsen, she mentions this effect when the US Army stood up the secretive 10th Special Forces after WWII. Even though it was the first of its kind the idea was that if the U.S.S.R found out about it they would worry there were 9 other such groups.

This differs by branch of service in the United States.

The UK actually has its regiments ordered by seniority