Ready conditions aren’t always the same, or the same for different handguns.
The most common start condition for handguns in USPSA (and Steel Challenge for Centerfire Divisions), is loaded and holstered. Any time a single action handgun is loaded with the hammer back, the safety must be applied as it goes into the holster or is placed on an object. (See this NROI Tips Video and 10.5.11)
Ready conditions are spelled out specifically in the rules for both disciplines, in Chapter 8.1, for all types of handguns. Double action guns, such as revolvers and selective action semi-autos can be started with the hammer down or back and a safety applied, if the division rules allow for it. For example, a CZ model selective action firearm with an external hammer must have the hammer down at the start signal in Production and Carry Optics divisions. In that case, the safety need not be applied as long as the hammer is down. That same handgun can be used in Limited or Limited-10 or Open divisions, though, and can start “cocked and locked”, i.e., hammer back (single action mode) with the safety applied.
It should be noted that the WSB may specify other ready conditions for the firearm. If the ready condition is “unloaded”, this means no ammo in the chamber, no loaded magazine in the mag well, and the slide or bolt must be closed, with the hammer down. (Yes, even for PCC, so when you remove the flag on one of these stages, you’ll have to dry fire the gun to get the hammer down.). That’s the default “unloaded” start condition. (See 8.1.3) But, the WSB could specify an empty chamber with a loaded magazine inserted. In that case, per the rules, that is a loaded gun. And, unless otherwise spelled out, the slide/bolt must be closed and the hammer down–in many cases, the safety cannot physically be applied, so it doesn’t have to be. See 8.1.2.5
Always be aware of the proper ready condition for your firearm, and pay attention to what the WSB says. Many competitors are shocked to hear that their slide/bolt must be forward and the hammer down (yes, even on your PCC) when faced with an unloaded start. Range Officers are sometimes surprised by this default condition as well.