Depends what coolant you use.
Not many companies use just acid. Just GM really.
Everyone else uses silicates or phosphates, with some exceptions depending on the year.
General rules: Japanese= phosphates, Euro= Silicates, GM= Acid, Ford/Chyrsler= G-05 aka Silicates. I think both Ford and Chrysler might have changed their minds recently.
VAG (Volkswagen Audi Group) used silicates, acid then back to silicates again. Three different colours/specifications.