30 JUNE 1906: TANAY, RIZAL to MANILA
4 times rated official mail with pair of 2c carmine Washington booklet pane issue of 1904
with small black manuscript "O.B." Backstamped MANILA on the same day.

THE ONLY RECORDED BOOKLET PANE PAIR WITH MANUSCRIPT OB ON COVER
2 JULY 1906: BOCAUE, BULACAN to MANILA,  written from BIGAA, BULACAN, 10 times rated official mail with 5c blue Lincoln x 2 issue of 1903 with black manuscript "OB." Backstamped MANILA on the same day.

20 SEPTEMBER 1906: BATANGAS to MANILA
Province of Batangas official mail, red manuscript “OB” on 1c Franklin, 4c Lincoln x 2, 15c Clay
and  black “OB” on 2c Washington, on  cover front for 18 times multiple registered rate
(18c + 8c Registry Fee), 9 ounces maximum weight.

15c CLAY OB UNCOMMON ON COVER
Frame 1 / Page 6
<Stamping Method
P-4
P-5
P-6
P-7
P-8
Type I Small O.B.>