For example:

The tooltip of the cellspacing of h:datatable is described by:

"Definition of how much space the user agent should leave between the left side of the table and the
leftmost column, the top of the table and the top of the top side of the topmost row, and so on for
the right and bottom of the table. It also specifies the amount of space to leave between cells."

It should also be said which measure I have to use for cellspacing. In this case (5 px or the like).

cellspacing="5", cellspacing="5px", cellspacing="5em",...

Would be nice, to say the allowed measures for all component-attributes where measures are required.