CobraMUSH maintains 30 levels 1-30. Only two are of particular real interest beyond how you wish to setup your game in particular.
Level 1 is also referred to as the guest level. Which realistically should never be set upon a player manually as Guests are auto-created in CobraMUSH. Along with the referenced behavior of auto-creating guests, guests are also automatically scheduled for destruction upon disconnection is the particular reason you should refrain from setting players level 1.
Level 30 is also referred to as the God level. Although there is a god player definition in the mush.cnf, level 30 inherits some of the God characteristics as well. And as any normal PennMUSHer knows performing maintenance on general systems and using the 'God' character for normal operations creates problems in the long run. So lets just take the advice here & now. Refrain from using level 30 for your System Directors, level 29 is meant for that.