MCO notation

Does anyone know why some moves in the MCO (Modern Chess Openings) have dots linking the columns together, while others don't?

Here is an example:

4   h4..........................................Bc4

     g4                                                   Bg7

5   Ne5                                                 h4

     Nf6.......Bg7            d6                    h6

Basicaly, that means that the top part of the columns is the same... for the four columns you have shown, the lines are, from left to right:

4. h4 g4 5. Ne5 Nf6

4. h4 g4 5. Ne5 Bg7

4. h4 g4 5. Ne5 d6

4. Bc4 Bg7 5. h4 h6

Does that make sense?

what was said above is correct, but MCO has typos in it so make sure you check the opening you are interested in, with anohter opening book or a program.  I remember studying Larsens opening with MCO 15 and just on that one opening found several mistakes. eg on page 730 of the Larsen's opening if you play out the moves to follow subscript E you will notice that the book on the 8th moved sacrifices the queen for no reason or advantage Fritz and chessmaster in the analysis mode call this an major error.

Also on same opening if you play out the move on column 5 and finally get to subscript L, you will notice it does not follow. It calls for the knight to take on D4 but there is no piece on d4. 

  This is on just one opening and from what I have been told by others there are plenty of other mistakes in that book, so they have issues with proofreading, so its best to study the opening with a program to make sure the lines are correct

Thanks Basballfan and Voltron5000. I understand that the move carries over as you go down the columns, but I'm still wondering if it makes a difference if there are "........" after a move or not. In the above example there are "......" after 4h4 and 5...Nf6 but not after 5Ne5, and I'm wondering if this means anything. I get the feeling it doesn't.