History: Document History


Used as a container for dates related to the processing and publication history of the document, such as the date last updated.


Conversion Note: The dates inside the <history> element are used to preserve events other than publication date(s) in the life cycle of a book or book component (such as a chapter). Publication dates are considered to be an important part of the metadata. History dates include received date, date last updated, reviewed date, and other dates that may be important to the publisher, but are not a likely part of the metadata for searching, building a DOI, etc.

The <history> element contains one more <date> and/or <string-date> elements; the <date> element has specific parts, such as day and year, inside it and the <string-date> has a textual description of a date. Best practice for the history element is to use to use <date> as much as possible and tag the date components. The <string-date> element should be used only when necessary, for example, when the date does not divide into year and month components. If an archive chooses to make greater use of <string-date>, for example, to save money during conversion, it is still considered best practice to tag the year of publication inside the textual date using a <year> element.

The NCBI Book DTD and NCBI Collection DTDs allow <string-date> both inside <date> and at the same level as <date>. This is the most flexible for allowing the archive to preserve any publisher’s structure. Tighter DTDs created from the base Suite may choose to use one or the other in preference.

Model Information

Content Model

<!ELEMENT  history      %history-model;                              >


One or more of any of:

This element may be contained in:

<book-meta> Book Metadata; <book-part-meta> Book Part Metadata; <collection-meta> Collection Metadata

Tagged Example


With various types of publication dates tagged (best practice):

<title>GenBank: The Nucleotide Sequence Database</title>
<date date-type="created">
<date date-type="updated">
<alternate-form xmlns:xlink="http://www.w3.org/1999/xlink" 
alternate-form-type="pdf" xlink:href="ch1d1"/>
<p>The GenBank sequence database is an annotated collection of all publicly 
available nucleotide sequences and their protein translations. This database 
is produced ...</p>