Final answer:
A file with long-term reference information updated periodically is called a reference file. It includes a bibliography and can contain almanacs, yearbooks, and authoritative reports, requiring examination of publication dates for relevance.
Step-by-step explanation:
A file containing relatively long-term information used as a source of reference and periodically updated with detail is termed a reference file. This type of file serves as a repository of information that is continuously maintained to ensure it remains current and relevant. Reference files often include a bibliography, which provides a comprehensive list of sources, including details like the author, title, publisher, and publication date.
Reference files are typically considered to be secondary sources because they compile and evaluate information from other published works rather than presenting original research. Resources such as almanacs, yearbooks, and reports from authoritative sources are examples of materials that could be included in a reference file. It's essential to evaluate the date of publication of items within a reference file to determine their relevance and accuracy in relation to the current times.