I was actually going to ask the exact same question that spiritofcat did (the same situation). But I don't think we have an clear answer here. Are there no standards for OTS2 defined anywhere? For me, I don't even know what makes a theme OTS2 or not, exept that it seems OTS2 dont use the step.rc for all the information, but using separate texdtfiles instead. But that can't be enough to defina an new standard, can it?