Castling Notation

For chess notation, is castling 0-0 or O-O.

The first is zeroes, the second is capital "o"s. Just wondering...

PGNs use the letter I believe.

lol, good question.

i've seen both - though i'm pretty sure that you shouldn't use slashed zeros...

According to pgn specification (http://www6.chessclub.com/help/PGN-spec):

kingside castling is indicated by the sequence "O-O"; queenside castling is indicated by the sequence "O-O-O". Note that the upper case letter "O" is used, not the digit zero

It's the zeros.

It's the O's.

O-O, or O-O-O is the correct notation.

We used to have to draw a stick figure doing the long jump.

You got it easy nowadays.

We used to castle uphill both ways in the snow.

You were lucky, we used to dream of that, we used to have to get up two hours before we went to bed, rub gravel in our hair for breakfast, and when we got home our Mom and Dad would thrash us to sleep with a broken bottle...if we were lucky : )

Gotta love the OP, not even refering to any specific chess notation. The way it used to be done was with castle and castle long. This stands for castling kingside and castling queenside respectively. I have never had to forefit a game because of using this notation. Let us assume you mean algebraic. If you want to know whether it is used with an O or a 0 (zero), read your FIDE handbook, appendix C, I think it is. They use zeros. However, if you were refering to ICCF notation 5171 is castling kingside, and 5131 is castling queenside.

It is right after appendix C.13 and they do appear to be zeros, although not actually stipulated as such.

zeros make more sense

I just use a capital zero. 

I've always used O's.

I use zeros.

One of my chess computer games says...

"Castleing kingside is O-O." It's the O's.

Okay, so I forgot queenside castling, or castling long. So what?

0-0-0

O-O-O is correct. in vote chess games, it says,

You voted for O-O-O, or O-O

using the O's, and not the zeros.

So you know because it's fatter? I've never seen any type of instruction for this!