Now naturally these places may be lying or underinspected, but per the guidelines, if it says "100% grass fed" or "grass-finished" it means they've only eaten forage their entire lives. Just "grass-fed" is BS goyslop.
The guidelines mean absolutely nothing if not backed by federal statutes really. Kind of like how “free range” means they just cut out a small opening in a crowded pen with the same, exact living conditions