INTER-ALLIED COMMISSION - ECONOMIC DEPARTMENT - SOCIAL INSURANCE, postage-free letter to Directorate of Reich Employee Insurance Institute, Berlin, double-circle OPPELN 7 4 22 * * g (OS handbook no. 237.19), blue double-circle official seal Commission de Gouvernement de Haute Silesie - Departement Economique - Assurances Sociales (OS handbook no. II.5.d). Although officials available since 1.4.1920, old violet fee-exemption mark Frei lt. Avers. No. 21 Pr. Regierung still used; this letter also illustrated in OS handbook (p. 62), age and use wear typical of period