maxsecondarystrikes= when did this show up and what does it do?

[Slant6 21]

Stumbled upon something called maxsecondarystrikes=[0,1 etc.] that I think limits the number of aircraft appearing in a campaign. Is this what it does, and if so, is it only for SF2? Why was this not mentioned in any readmes? Is it like the config.ini commands in Il-2FB that limit the amount of planes in a campaign, improving framerate and if so, is it the only way to do so? Thanks.

[Gr.Viper 131]

In recent game versions, especially over Nam, sometimes you'll see that there's another flight performing a strike mission against your target. That seems to be the value responsible for them in some way.