I've read here and other places to use only ones with the certification number on it. After reading all the labels at AZ and Advance, only Advance's house brand had a certification number listed. Castrol said something close to "certified by the major manufacturers", but even their web site didn't go into any more detail, and the rest said something like "surpasses other Dexron III fluids" or "recommended for all Dexron fluid applications".
Bearing in mind that in marketing what ISN'T said is more important than what is, and that the certification number is only 6 or 7 characters, there must be some reason they don't brag about that or list it too... at least in the fine print.
If the advice is correct, look for the number. Let us know if you find any other brands willing to put it on the bottle too. I'm not a fan of house brands usually... :looney: