This is a grey area. Edifil (Ediciones Filatélicas) is a private company that invests heavily in research. The latest editions (2023, 2024, 2025) are protected by copyright. However, many collectors seek (e.g., 1990s or early 2000s) which are no longer commercially available.
: It provides updated market prices and, in recent editions, includes separate columns for different quality grades, such as "luxury" vs. "normal" condition. This is a grey area