Just found this site which gives a listing of commercial brake fluids.
http://www.doacs.state.fl.us/standard/petro/bfbrands.html
The basis of their being "acceptable" is probably the result of some laboratory testing to certify that the fluids meet a sampling of the tests that are called out under SAE J1703 or J1704. The State of Florida for many years has conducted routine testing of motor fuels, oils, and other products to determine whether the produt in question meets the industry standard. On the above site, you can switch to their listing of acceptable antifreezes.
http://www.doacs.state.fl.us/standard/petro/bfbrands.html
The basis of their being "acceptable" is probably the result of some laboratory testing to certify that the fluids meet a sampling of the tests that are called out under SAE J1703 or J1704. The State of Florida for many years has conducted routine testing of motor fuels, oils, and other products to determine whether the produt in question meets the industry standard. On the above site, you can switch to their listing of acceptable antifreezes.