Ah OK. I had read about % vs. %% and %%% but it hadn't registered, perhaps
because it smelled perl-ish and thus went in one ear, out the other.
In the brain-damaged language(s) the other gentleman was referring to,
emacs will automatically indent the comment line according to its position
in the code, without need for any of that %% or %%% flummery ;-) That is
both more natural and more practical, I think. But I can live with %%.