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

   The /SYNTAX_CHECK qualifier  causes  VAX  BASIC  to  perform  line-by-line
   syntax checking.

   The format of the /SYNTAX_CHECK qualifier is as follows:

      /[NO]SYNTAX_CHECK

   When syntax checking is enabled, VAX BASIC immediately checks  the  syntax
   of  every  text  line  as soon as you type a carriage return.  When syntax
   checking is disabled, VAX BASIC does not perform syntax checking until you
   COMPILE or RUN the program.

   The /NOSYNTAX_CHECK qualifier causes VAX BASIC  to  suppress  line-by-line
   syntax checking.

   The default is /NOSYNTAX_CHECK.