A -3 appears in the misc AC bonus spot for no reason. It does not get added into the total AC.
-3 was due to math coding in the OS "MISC" field, taking away equipment bonus. This is actually handled in the gamemode. The math was causing a deficit and pointless since it had no impact upon final totals.
Side note: Everything in modern is self-contained, and not modular. The Preview sheet needs a serious upgrade.