BITS 2.0
( #PCDATA | addr-line | city | country | fax | institution | institution-wrap | phone
| postal-code | state | address | email | ext-link | uri | label | anonymous | collab
| collab-alternatives | name | name-alternatives | string-name | role | fn | target
| xref | x )*
BITS 2.1
NO CHANGE IN CONTENT MODEL