GROUP            Define Segment Group                          MASM Directive

  name      GROUP     segmentname,,,

    Causes the assembler to associate name with one or more segments, so
    that all labels and variables defined in those segments have their
    offsets computed relative to the beginning of name.

       Notes:     The name argument must be unique, and the segmentName
                  argument must be a segment previously defined with a
                  SEGMENT directive or a SEG expression.

                  A group's segments need not be contiguous.  Segments not
                  belonging to the group can be loaded between segments
                  that do.  There is a restriction in that the first byte
                  of the first segment in the group must not be greater
                  than 65,535 bytes away from the last byte of the last
                  segment of the group.  This means that if all the
                  segments of a group are contiguous, a group can be no
                  larger than 65,536 bytes, or 64K.

                  The name argument must not be in any other GROUP
                  directive in any source file.

                  The group name can be used in any ASSUME directive
                  statements and can also be used with segment overrides.