VMS Help CC, /MEMBER_ALIGNMENT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

     /MEMBER_ALIGNMENT (D)
     /NOMEMBER_ALIGNMENT

  Directs the compiler to naturally align data structure members.
  This means that data structure members are aligned on the next
  boundary appropriate to the type of the member, rather than on the
  next byte.  For instance, a long variable member is aligned on the
  next longword boundary; a short variable member is aligned on the
  next word boundary.

  Any use of the #pragma member_alignment or #pragma
  nomember_alignment directives within the source code overrides the
  setting established by this qualifier.  Specifying
  /NOMEMBER_ALIGNMENT causes data structure members to be
  byte-aligned (with the exception of bit-field members).

  For OpenVMS Alpha systems, the default is /MEMBER_ALIGNMENT.

  For OpenVMS VAX systems, the default is /NOMEMBER_ALIGNMENT.