I was working on helping a user figure out how to accomplish something in their custom sheet code when this weird treatment of radio buttons was pointed out. It does not appear to have any functional effect on the radio. Repeating section radio buttons get the reprowid and "repeating" prepended to their attribute names in the parsed html. This winds up looking like this: Note, the start of the highlighted radio button's name. This is the only html element type that this occurs to that I've found so far. And, while this appears to have no effect on the functionality of the element, it does make it confusing for new sheet authors who are inspecting their sheets during development.