"Not known" (Type I13) and "RETOUR" (Type I19) h.s., the last two with Economy Label affixed over the top. Photo" /> cover 1942 (16 June) locally addressed U5, bearing Straits 8c. with single frame chop in red, clearly cancelled by bi-lingual Syonan c.d.s. and showing large "RETURN TO SENDER" h.s. in violet (Type I12) with, on reverse, unframed <I>"Not known"</I> (Type I13) and "RETOUR" (Type I19) h.s., the last two with Economy Label affixed over the top. Photo | Christie's