How long since the copyright of a book is a criteria for judging its relevance in the MUSTIE weeding process?

In the MUSTIE weeding process, the criterion regarding the age of the copyright helps librarians assess the relevance of a book in relation to the current needs and interests of users. A book that is three years old or newer is generally considered more likely to contain current and relevant information, as it reflects more recent research, developments, and changes in any given field. The three-year mark indicates that the material is likely to be current enough to serve the needs of patrons effectively, making it a pertinent guideline for weeding decisions. Materials that are significantly older may no longer represent the most accurate or up-to-date information available. Thus, in this context, three years serves as a practical benchmark for evaluating the ongoing relevance of library materials.