[11] SystemLiteral ::= ('"' [^"]* '"') | ("'" [^']* "'")
[75]  ExternalID     ::= 'SYSTEM' S SystemLiteral | 
                                 'PUBLIC' S PubidLiteral S SystemLiteral
Christina Portillo   
Product Definition and Image Technology
The Boeing Company               Phone: 425.237.3351
PO Box 3707   M/S 6H-AF       Fax:     425.237.3428
Seattle, WA  98124-2207         christina.portillo@boeing.com