Edition Statements: Edition statements (<edition>) in BITS books are allowed both within the book metadata (<book-meta>, <book-part-meta>, <collection-meta>, etc.) and within citations (<mixed-citation> or <element-citation>). In both uses, edition statements are frequently given as ordinal numbers (first, second, third, etc.) and often abbreviated with a “th”, “rd”, or similar suffix. These ordinals may either directly follow the number (4th) or be placed in a superscript following the number (4^th). BITS allows some flexibility in placing these ordinals, and each publisher or archive will need to decide whether or not these ordinal suffixes are part of the <edition> element’s content.

For example, consider the edition statement “3rd” used within a <mixed-citation>:

• Archives and publishers who wish to regularize content for searching can eliminate these extra characters and tag the edition as <edition>3<edition>.
• Archives who wish record each detail of the printed volume exactly can retain these extra characters:
  • inside the edition statement: <edition>3^rd<edition>
  • outside the edition statement inside the text of a mixed citation: <edition>3<edition>^rd or
  • inside the edition statement, using the @designator attribute to preserve the edition number:

    <edition designator="3">3<sup>rd</sup></edition>
    

Volume Numbers: In BITS books, the volume number element (<volume>) is used only inside citations and not as part of book metadata. Inside citations (<mixed-citation> or <element-citation>), a volume number with ordinals can be:

• inside the volume number: <volume>1^st<volume> or
• outside the volume number inside the text of a mixed citation: <volume>1<volume>^st

The related <volume-id> element is used to record an identifier, such as a DOI, that describes an entire volume of a journal or series.