CMP Rimfire Sporter rule question: initial position?

[LRCampos]

We are implementing the CMP Rimfire Sporter matches in our country and reading the rules, it says that:

8.5.3 Rapid Fire Procedures
...
Assuming Positions. Competitors begin all rapid fire stages from the standing ready position.
...


The only video I saw on a rapid fire CMP Rimfire Sporter match (here in accurate shooter.com) shows that all competitors started already in seatting or kneeling position.

On the CMP Nationals, which position does the competitors starts the Rapid Fire stage: standing or already in prone or seating position?


I know that there are few exceptions on this rule, like who has physical limitations etc.


LRCampos.