Serves as a hook for book-specific processing, for example, to allow one page number to be marked as primary; to distinguish between printed numbers provided by a publisher and penciled numbers added by a library; or to make other pagination distinctions
| Value | Meaning |
|---|---|
| Text, numbers, or special characters | The type of page number, for example, a printed number provided by a publisher, a number added by a library, etc. (Note: An also permissible value is “implied” to indicate the number may be implied.) |
| Restriction: This attribute may be specified if the element is used. | |