> I'd like this same facility with elog.  Now I know that it can be
> done by (for example) in the config file preselecting one of the
> selections on reply- or indeed one that does not exist to "clear" it, 
> but in this case that is not the route I'd want to take every time.

What about defining an additional option "unspecified". So you have

Roptions attr = option1, option2, option3, none

Whenever you click on "none", the selection is removed from the other options. The HTML standard unfortunately does 
not foresee radio buttons not being selected, so I would have to tweak it somehow to get exactly what you want.