Final answer:
A loose-leaf log contained within a separate cover and used for selected items of SE is a logbook, which is a document used to record important information in various fields.
Step-by-step explanation:
A loose-leaf log contained within a separate cover and used for selected items of SE refers to a logbook. A logbook is a document used in various fields to record important information, such as events, observations, or data. It provides a written record that can be referred back to for reference or analysis. For example, in the maritime industry, logbooks are used to record the details of a ship's journey.