Command line syntax and options as listed in the 5.0 manual:

        MASM [options] sourcefile [,[objectfile] [,[listingfile] [,[crossreferencefile]]]] [;]

/A- Writes segments in alphabetical order
/Bnumber- Sets buffer size
/C- Specifies a cross-reference file
/D- Creates Pass 1 listing
/Dsymbol[=value]- Defines assembler symbol
/E- Creates code for emulated floating-point instructions
/H- Lists command-line syntax and all assembler options
/Ipath- Sets include-file search path
/L- Specifies an assembly-listing file
/ML- Makes names case sensitive
/MU- Converts names to uppercase letters
/MX- Makes public and external names case sensitive
/N- Suppresses tables in listing file
/P- Checks for impure code
/S- Writes segments in source-code order
/T- Suppresses messages for successful assembly
/V- Displays extra statistics to screen
/W{ 0 | 1 | 2 }- Sets error-display level
/X- Includes false conditionals in listings
/Z- Displays error lines on screen
/ZD- Puts line-number information in the object file
/ZI- Puts symbolic and line-number information in the object file