What variables are necessary in a new user/group creation

I am working on a script using dscl to automate creation of a user and group. I have looked at scripts out there but none of them create the variable “generateuid”. This variable is listed in both the user and group properties as viewed through Netinfo Manager when examining accounts generated by the System Accounts dialog in System Preferences. What is the generateuid variable and is it necessary for user and/or group accounts?

Thanks!