| year |
first day |
country |
scott # |
agency |
conference |
conference dates |
conference city |
| 1930 | 23-apr | france | 256-257 | ilo | 48th session of ilo governing body | 24-29 apr 1930 | paris |
 |
| 1930 | 5-oct | belgium | 222-224 | ilo | 50th session of ilo governing body | 7-12 oct 1930 | brussels |
 |
| 1932 | 2-feb | switzerland | 210-215, c16-18 | lon | conference for the reduction and limitation of armaments | 2 feb-23 jul 1932 | geneva |
 |
| 1932 | 2-feb | switzerland | 2o36-41 | lon | conference for the reduction and limitation of armaments | 2 feb-23 jul 1932 | geneva |
 |
| 1932 | 2-feb | switzerland | 3o32-37 | lon | conference for the reduction and limitation of armaments | 2 feb-23 jul 1932 | geneva |
 |
 |
| 1933 | 18-may | canada | 202 | upu | preparatory committee for 10th congress | 18 may-28 jun 1933 | ottawa |
 |
| 1934 | 1-feb | egypt | 177-190 | upu | 10th universal postal congress | 1 feb-20 mar 1934 | cairo |
 |
| 1937 | 6-oct | czechoslovakia | 236-238 | ilo | 81st session of ilo governing body | 6-9 oct 1937 | prague |
   |
| 1938 | 1-feb | egypt | 228-230 | itu | international telecommunications conference | 1 feb-8 apr 1938 | cairo |
 |
| 1939 | 1-apr | argentina | 459-66 | upu | 11th universal postal congress | 1apr -23 may 1939 | buenos aires |
 |
| 1939 | 12-may | argentina | 467-468 | upu | 11th universal postal congress | 1apr -23 may 1939 | buenos aires |
 |
