No ads, no public displays of drug use, no public drug use, not even in designated public venues, and no brown paper bag bullshit either. Keep it private. No operating heavy machinery or participation in traffic while intoxicated. But yeah, the drug use itself should not be criminal.
No ads? OK, sounds reasonable. No public display? OK, we don't allow this for alcohol EXCEPT in designated venues. Do you see a problem with pot cafes? Or methadone clinics? If by public you mean on the street OK, but if you mean no consumption anywhere except the home this contradicts how we treat alcohol. No brown paper bag bullshit? Well you don't usually drink drugs, so OK. No operating machinery or participating in traffic while intoxicated? OK, although proving this for many drugs is much more challenging than alcohol. Example: marijuana.