I think the engraver means Johnson was the RSM.So, another family visit has yielded another QSA. It's been contemporary renamed, but that's not unusual. Any chance of a quick look up? Named to 1036 Pte JR Johnson 5th MI Bdge [sic]. Whoever engraved it didn't know how to correctly abbreviate 'brigade'. I am, however, intrigued as to clasp entitlement and actual unit.