My question involves criminal law for the state of: VA

I was hoping for clarity on an issue regarding the no alcohol clause after a DUI conviction. Two coworkers have been convicted of DUI, and were allowed to consume alcohol while on probation. Granted, both abstained during the mandatory ASAP program. Another friend of mine is currently on probation for his third DUI, and has a no consuming alcohol clause as part of his probation.

My question is: are no alcohol clauses assigned on a case-by-case basis or are they typically assigned to habitual offenders? Are they uncommon for first DUI offenses, or was this clause overlooked for the two coworkers of mine?