Formats given are strongly encouraged but not mandatory; if non-standard datetime values are used in <time> elements, always use the datetime attribute.


Property value takes the chronology (issue date) of the periodical in the following format:


using the following abbreviations for the months:

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

For quarterly issues:

Win Spr Sum Aut

Always use the required datetime attribute:

<time itemprop="pr_chronology" title="Issue Date" datetime="2009-10">Oct 2009</time>

<time itemprop="pr_chronology" title="Issue Date" datetime="1943-01-19">19 Jan 1943</time>

For quarterly issues, use the month the season starts in the datetime attribute:

<time itemprop="pr_chronology" title="Issue Date" datetime="1977-03">Spr 1977</time>

For special issues, such as holiday issues, spell out chronology in full and use the month the holiday falls in or the event starts in the datetime attribute:

<time itemprop="pr_chronology" title="Issue Date" datetime="2007-12">Christmas 2007</time>

<time itemprop="pr_chronology" title="Issue Date" datetime="1988-12-03">Hanukkah 1988</time>


Property value takes a counting number, i.e. the integers greater than 0 (zero).


Property value generally takes an ordinal number, e.g.: 1st, 2nd, 3rd, 4th, etc., followed by abbreviation edn. outside containing element.

<span itemprop="bk_edition" title="Edition">5th</span> <abbr title="edition">edn</abbr>.

May take any edition value listed in source.


Property value takes the enumeration (volume and number) of the periodical in the following format:


<span itemprop="pr_enum_volume" title="Volume">43</span>:<!--
--><span itemprop="pr_enum_number" title="Number">

Always use digital values; e.g., for "IV" use "4".


Property takes one of the following values: Print, Audiobook, EBook, GraphicNovel, Hardcover, Paperback


Property value is always in the format:

[surname], [given_name] [initial.(s).]:

<span itemprop="bk_author" title="Author">Glasheen, Adaline</span>.
<span itemprop="bk_author" title="Author">Van Caspel, Paul P. J.</span>
<span itemprop="bk_author" title="Author">Litz, A. Walton</span>.

Use standardized form from the Library of Congress authority records, if possible. If multiple names are listed for a given property (multiple authors, multiple editors, etc.) use a double ampersand between names:

<span itemprop="bk_author" title="Author">Wilder, Thornton</span> &amp;&amp;
<span itemprop="bk_author" title="Author">Glasheen, Adaline</span>.


Property value is the publisher's name per the guidelines in the MLA Handbook, 7th edn., section 7.5, pp. 247-249.


Property value takes any applicable UTF-8 plain text.


Property value takes the book title, as listed on the title page or in source, in sentence case.

<cite itemprop="bk_title" title="Book Title">A portrait of the artist as a young man</cite>.
<cite itemprop="bk_title" title="Book Title">The Bloomsday book: a guide through Joyce's 'Ulysses'</cite>.


Four digit year in the following format:


<time itemprop="bk_year_published" title="Year Published">1959</time>.

datetime attribute is not required since the format is already an accepted datetime value.