Different ranges have different commands. At all the ones that I have shot at, they are in fact pretty informal about the exact form of the command.
The one I like to go to is extremely formal about the actions - but not necessarily the commands. There usually a warning about the range going cold in a minute or so, which means, "Shoot what you have in magazine or a cylinder but don't reload."
Then there a "Range is going cold!" type command - that means lay your weapons on the range table, with magazines out and actions open.
When the range is cold, you don't touch any weapon for any reason (you can't put in a case, take it out of a case, pick it up to show anyone, etc.) Touching the weapon for any reason will earn you a visit from the RSO.
The visit may be a gentle reminder, or it may be more in your face. If it's your first attempt, or you had a momentary brain fart when someone asked a question about your handgun - and you admit your stupidity -, the reminder will be gentle.
If you are a multiple offender, or you try to enlighten the range officer as to why what you were doing was really safe, the reminder will get progressively less gentle until you admit your guilt or are ejected.
There was one guy at the range when I was shooting, and he was determined to let the RSO know that it was perfectly safe to put his pistol in the case while folks were down range - to be honest, that's the only time that I have ever heard an RSO raise his/her voice there. The guy was eventually ejected, with a bunch us watching him walk out. My own stereotypical thinknig was that he was a laywer or a doctor, who wasn't used to immediately obeying orders from anyone. As I watched him walk out, I thought, "That is exactly why I drive 20 minutes farther to shoot at this range!"
Most of the time, when the RSO walks over to you, you understand that you have made a mistake and are red-faced.
Then the RSO calls out some version of "the range is going hot", then you can relaod, and shoot.
I have never shot in a formal match, but when I have visited a range, they have all more or less worked like this. When there is no RSO, just talk to the people on the line. Even if they don't use the "hot" and "cold" terminology, at every place I have been, they have been very nice about answernig questions and explaining the terminology they did use.
PCV Yemen 84-86
Ahalan wa sahlan.
Past results are no guarantee of future performance.