documentCode property
The document code. Document code contains two characters.
For MRTD the first character shall be A, C or I.
The second character shall be discretion of the issuing State or organization except
that V shall not be used, and C shall not be used after A except in the crew member certificate.
On machine-readable passports (MRP) first character shall be P to designate an MRP. One additional
letter may be used, at the discretion of the issuing State or organization, to designate a particular
MRP.
If the second character position is not used for this purpose, it shall be filled by the filter character.
Implementation
String? documentCode;