4d blue on cream GV postal stationery envelope (H&G C2) used with added pair 1910 2½d blue 'Opening of Union Parliament' issue (SG 2) tied on reverse by two strikes of OUDTSHOORN cds dated NO 25 1912 with additional strikes on front along with boxed 'OUDTSHOORN registration marking in blue. Addressed to GERMANY with transit marks on reverse. A nice registered use of the Union issue. Note that H&G records this envelope as being issued in 1918, 6 years after this use.