/sys$common/syshlp/helplib.hlb FORTRAN, /CHECK  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /[NO]CHECK[=(option[,...])] D=/CHECK=(NOALI,NOASS,NOBOU,OVERFL,NOUND)

  Controls whether the compiler produces extra code to check for
  certain error conditions at run time.

  The default is /CHECK=OVERFLOW.  This qualifier can also be
  specified on the OPTIONS statement.

  The qualifiers /CHECK and /CHECK=ALL are equivalent, as are
  /NOCHECK and /CHECK=NONE.

  Additional Information (explode) :

• ALIGNMENT
• ASSERTIONS
• BOUNDS
• OVERFLOW
• UNDERFLOW
• ALL
• NONE