What the ':=<0>' mean?

[UtillMasm]

Code Select Expand

;...
FILE_DEVICE_UNKNOWN equ 22h
METHOD_BUFFERED equ 0
FILE_READ_ACCESS equ 1
FILE_WRITE_ACCESS equ 2
;...
CTL_CODE macro DeviceType:=<0>,Function:=<0>,Method:=<0>,Access:=<0>
  exitm %(((DeviceType) shl 16) or ((Access) shl 14) or ((Function) shl 2) or (Method))
endm
;...
IOCTL_GET_PHYS_ADDRESS equ CTL_CODE(FILE_DEVICE_UNKNOWN,800h,METHOD_BUFFERED,FILE_READ_ACCESS+FILE_WRITE_ACCESS)
;...
Help! Help! Help!

[dedndave]

it must be part of the label name   :bg
ohhhh - i bet those are locals - the ":" is the scope   :U

[sinsi]

If you skip a parameter the text in the angles is the default value.

[UtillMasm]

 :U
how to skip a (the 'DeviceType') parameter:

Code Select Expand

IOCTL_GET_PHYS_ADDRESS equ CTL_CODE(,800h,METHOD_BUFFERED,FILE_READ_ACCESS+FILE_WRITE_ACCESS)
any other way to skip a parameter?