In a rapidly changing digital world, repositories stand for reliable and long-term available information and resources that make research results transparent and comprehensible, thus serving as a basis for new scientific research. Early on, the need for quality control and certification of this stability and “trustworthiness” was recognized, which was reflected in various certification initiatives. The contribution outlines the concept of “trust” and gives an overview of criteria and certification guidelines that are especially used in the humanities and the library sectors.