Length and Size

This Tag Set has a single general purpose element <size> for recording the number of pages in a book, the showing time of a film, the number of kilo/mega/tera-bytes in a dataset, or any other measurement of size, length, or extent that may be recorded for a cited work. The @units attribute should be used whenever possible to state the units of measure, such as “pages”, “minutes”, “paragraphs”, “MB”, etc., which is typically given in the plural.

Sizes and Units

In both styles of citations (<mixed-citation> and <element-citation>), Best Practice for naming sizes and units is:
  • The <size> element holds the number, length, etc. of objects (“4”, “12” “368”)
  • The required @units attribute holds the canonical value of the unit (“leaves”, “pages”, “seconds”, etc.), and
  • The displayable value of the unit is recorded separately (see below).
Mixed Citations — Best Practice for mixed-style citations (<mixed-citation>) is to place the unit display text into the free text of the citation. The unit display should never be inside the <size> element.
<mixed-citation publication-type="conf-proc">
 <size units="pages">385</size> p. <comment>(Progress in
 brain research; vol. 147)</comment>
Element Citations — In element-style citations (<element-citation>), there is no one Best Practice for recording displayable units. The units in the text can be handled in several ways:
  • Best if possible. If the @units attribute value has been tagged consistently, the unit display text can be generated on display and does not have to be included in the element content:
    <size units="pages">256</size>
  • If the publisher or archive does not wish to generate text based on the attribute (or cannot, for example, if the attributes have not been tagged consistently), there are no good answers, but the display of the unit text can be handled (awkwardly):
    • Included as content of a <comment> or an <x> element
      <size units="pages">256</size><comment> p.</comment>
    • If all else fails. Included as content in the <size> tag:
    <size units="pages">256 pages</size>
<size> compared to <book-page-count>
The <size> records information about cited material. The <book-page-count> element is document-level metadata that records similar page-size information for the work rather than for cited material. The <size> and <book-page-count> are modeled very differently. The size element is assumed to contain the textual value of the size:
<size units="paragraphs">8</size>
while the page count element is an EMPTY element that stores its value in the @count attribute:
<book-page-count count="26"/>