Why is '//' style multiline comment bad (in Java)?

Question

http://java.sun.com/docs/codeconv/html/CodeConventions.doc4.html#286

I was reading the above section of Java coding convention and started to wonder why it says \"// com

Answer 1

I will say that I wouldn't call it "bad". Really, its a matter of convention, which is what others have said. There is nothing inherently bad about it, except that it can make multi-line comments a bit more frustrating (keystrokes-wise) to work with.

Honestly, I think it is a double standard with javadoc. Javadoc requires:

/**
 * Validates a chess move. Use {@link #doMove(int, int, int, int)} to move a piece.
 * 
 * @param theFromFile file from which a piece is being moved
 * @param theFromRank rank from which a piece is being moved
 * @param theToFile   file to which a piece is being moved
 * @param theToRank   rank to which a piece is being moved
 * @return            true if the chess move is valid, otherwise false
 */

and I don't understand why the repeated " * " is any better than "//". So, to me, there's nothing inherent about // being bad (because editors can be set up to automatically add them to multi-line comments) and just convention and common practice.