Thanks. I think I'll try the # style then.
It would be good if someone using Marmalade can confirm that it actually works before I check in the changes.
I just checked and can confirm that '//' comments are not allowed; using '#' instead '//' is allowed but only at the beginning of the line... arm assembler uses '#' as a part of operands.
'/*.. */' is allowed everywhere and probably would be the best solution.