If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.
I know them as grease pencils or china markers (will write on porcelain).
Check the wiki for "grease pencil" (I tried to post the link, but as a new user the post was auto-deleted - and it took me a moment to find out why - the warning flashed by before I could finish reading it...my bad)
I have red and black and white in my darkroom. Useful items.