The article describes the characteristics of the SCU3 specific competency unit: Management of document collections, within the occupational standard for librarians (higher education) developed by the specialists with the National Library of Romania, Romanian Librarians' Association (RLA) and Romanian National Association of Librarians and Public Libraries (RNAPL). It presents the competency elements (establishing policies and preparing collection development plans, publishing market prospection, selection/deselection of documents, promoting cultural values, etc.), the achievement criteria associated to the results of the activities described by each competency element (establishing policies based on the library mission and functions, types of users, prospecting the market in conjunction with the collections and taking into account the users' requirements, (de) selecting documents according to the available resources, setting up collections, by various methods, depending on the target public and according to the development plan, promotional activities based on the available financial resources, etc.) and the achievement criteria associated to the level of performance of the activity described by the adequate competency element (careful assigning, discerning, consistent promoting, etc.), considering the context (internal spaces, silence, constant intellectual effort, etc.), the variables that may occur (types of documents, objectives, library mission and functions, types of users, publishing market, etc.) and the librarians' knowledge [ABSTRACT FROM AUTHOR]