Hi,

I was looking at the HTML 4.01 DTD at http://www.w3.org/TR/html4/strict.dtd 
to look at the table definition.

<!ELEMENT TABLE - -
     (CAPTION?, (COL*|COLGROUP*), THEAD?, TFOOT?, TBODY+)>
<!ELEMENT CAPTION  - - (%inline;)*     -- table caption -->
<!ELEMENT THEAD    - O (TR)+           -- table header -->
<!ELEMENT TFOOT    - O (TR)+           -- table footer -->
<!ELEMENT TBODY    O O (TR)+           -- table body -->
<!ELEMENT COLGROUP - O (COL)*          -- table column group -->
<!ELEMENT COL      - O EMPTY           -- table column -->
<!ELEMENT TR       - O (TH|TD)+        -- table row -->
<!ELEMENT (TH|TD)  - O (%flow;)*       -- table header cell, table data
cell-->

This definition seems to me that a TR tag is not allowed to be a direct
child of
a TABLE tag. This surprised me... Also because when I validate a 4.01
document
with the w3c validator it says it is valid.

Could someone explain this?

Also what is this about the "- O", "O O" and "- -"? What does that mean?
When I write my own DTD I am not allowed to write comments with -- 
comment --
yet W3C uses it everywhere.

Thanks for any help.