I knew there were to be names associated with commenting styles, but I'd never seen conditional comments before, so was quite surprised when I 'invented' them myself!
They are pretty ugly IMO - even with descriptive text, the syntax of conditional commenting is untidy and as every programmer knows (but rarely abides to), good code is clean code

The commenting symbols have no structure - at least with a slash-star you know there has to be a star-slash somewhere else for it....