VMS Help PASCAL, Attributes, POS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  POS forces the field (of a  packed  or  unpacked  record)  to  a
  specific bit position within the record.

  Syntax:

     POS( n )

  The constant expression 'n' specifies the bit location, relative
  to the beginning of the record, at which the field begins.

  See the  "Compaq  Pascal  Language  Reference  Manual"  for  the
  complete description of using the POS attribute.