X00 Subfield $b - Numeration:

Subfield $b contains a roman numeral or a roman numeral and a subsequent part of a forename. It is used only in a forename heading (first indicator, value 0 ).

Examples:

100 0#$aJohn Paul$bII,$cPope,$d1920-

100 0#$aJohn$bII Comnenus,$cEmperor of the East,$d1088-1143.