Defines the @rules attribute, its values, and default for use in attribute lists in NISO JATS table model (based on and designed to be converted
easily to the XHTML 1.1 table model).
Remarks
The @rulesattribute defines which rules to draw
between cells in a NISO JATS table.
Model
<!ENTITY % rules.attrib
"rules ( none
| groups
| rows
| cols
| all ) #IMPLIED"
>