External data entity notation's PUBLIC identifier not given in LIBRARY declaration.
          #6026   Run-time catchable error
          External data entity notation's PUBLIC identifier not given in LIBRARY declaration.
Additional Information
 For element 'X' : For attribute 'Y' = "Z",
notation is 'A' and public id is 'B'.
     where Z is the name of the attribute's external entity.
     or
 For external entity 'X', notation is 'Y' and public id is 'Z'.
Explanation
An external entity's notation has a specified public identifier
which was not defined by a library declaration in the
OmniMark program.