English: Decree on official language on the Trans-Olza/Olše/Olsa Silesia territory (in Polish "Śląsk Zaolzański") after being forcibly annexed by Poland in October 1938 (before the annexation the territory was part of Czechoslovakia and now it is part of the Czech Republic and, to a very small extent, also Slovakia). The decree was made by the Deputy of the Silesian Voivode on 8th October, 1938 in Cieszyn Zachodni (Western Cieszyn, Český Těšín before the annexation) after the Polish Army seized the territory. The Decree declared the Polish Language to be the sole official language on the annexed territory. All names of streets, squares, parks, etc., as well as firm names, names of institutions, enterprises, etc., regardless of being public or private had to be in the Polish Language only. The Decree became effective as of the date of its publication on 10th October, 1938. The decree ended Czech-Polish bilinguality existing on the territory before its annexation and also ended usage of German for names of privately held firms, enterprises, and private institutions.