In the ps1 and ps2 system.cnf, what is the difference between boot = and boot2?

[SCO]

I'm hoping this is a easy way to figure out if a cd/dvd iso is ps1 or ps2. If it's not, drop a hint if you know ok?
January 11, 2018, 05:27:29 AM - (Auto Merged - Double Posts are not allowed before 7 days.)
Apparently yes. Or as far as i've been able to figure. Must be part of the ps2 retrocompatibility with the ps1.