SGML Example

<!ELEMENT COMPANY - - (name?, product?)>
<!ELEMENT NAME - O (#PCDATA)>
<!ELEMENT PRODUCT - - (item*)>
<!ELEMENT ITEM - O (#PCDATA)>
...
<!ENTITY ....>
...
<!ATLIST COMPANY
         type      (non-profit | limited | corporation) >
...
<COMPANY type=corporation>
<NAME>Megahard
<PRODUCT>
<ITEM> Apartments
<ITEM> Automobiles
<LI>...
</PRODUCT>
</COMPANY>