XREF [.<size>] <symbol>[,<symbol>]...
where <size> = B(direct ), W (default), or L or S or T.
EXTERNAL
This directive specifies symbols referenced in the current module but defined in another module. The list of symbols and corresponding 32-bit values is passed to the linker.
The number of symbols enumerated in an XREF directive is only limited by the memory available at assembly time.
The S and T size designators are only available for S12Z, and result in marking the symbol as short or tiny.
XREF OtherGlobal ; Reference "OtherGlobal" defined in
; another module. (See the XDEF
; directive example.)