Audience note

Use of the Audience Note (MARC 521 field) is recommended when the information is readily available, but is not required. This note is especially useful for Reader Levels (RL) and Interest Levels (IL) for children's books, MPAA ratings for video recordings, ESRB ratings for video games, and recommended reader levels (e.g. "For mature readers" or "Teen 16+") for graphic novels. Lexile numbers are are also coded in this field, but have their own data entry guidelines. Lexile levels are supplied by Marcive. For multiple statements, use multiple fields.

Differences in the contents of the 521 field do not warrant creating a new record except for video games and video recordings, because a difference in the MPAA rating or the ESRB rating may indicate a significant difference in content.