<conversion>

<conversion> defines how to calculate one unit of measure in terms of another. [2.3.9 The Unit Declaration]
Module header — The TEI Header
Attributes
calendar⚓︎ indicates one or more systems or calendars to which the date represented by the content of this element belongs.
Deprecated This feature will be withdrawn after 2024-11-11
Status Optional
Datatype 1–∞ occurrences of teidata.pointer separated by whitespace
Schematron

<sch:rule context="tei:*[@calendar]">
<sch:assert test="string-length( normalize-space(.) ) gt 0"> @calendar indicates one or more
systems or calendars to which the date represented by the content of this element belongs,
but this <sch:name/> element has no textual content.</sch:assert>
</sch:rule>
fromUnit⚓︎ indicates a source unit of measure that is to be converted into another unit indicated in toUnit.
Status Required
Datatype teidata.pointer
toUnit⚓︎ the target unit of measurement for a conversion from a source unit referenced in fromUnit.
Status Required
Datatype teidata.pointer
Contained by
header: unitDef
May contain Empty element
Note

The conversion element is designed to store information about converting from one unit of measurement to another. The formula attribute holds an XPath expression that indicates how the measurement system in fromUnit is converted to the system in toUnit. Do not confuse the usage of the dating attributes (from and to) in the examples with the attributes (fromUnit and toUnit) designed to reference units of measure.
Example
<conversion fromUnit="#shilling"
 toUnit="#pence" formula="$fromUnit * 12" from="1707"
 to="1971"/>
Example
<conversion fromUnit="#pound"
 toUnit="#shilling" formula="$fromUnit * 20" from="1701"
 to="1971"/>
Content model 
<content>
 <empty/>
</content>
Schema Declaration 
<rng:element name="conversion">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.rendition.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:ref name="att.global.source.attributes"/>
 <rng:ref name="att.datable.attributes"/>
 <rng:ref name="att.datable.w3c.attributes"/>
 <rng:ref name="att.datable.iso.attributes"/>
 <rng:ref name="att.datable.custom.attributes"/>
 <rng:ref name="att.formula.attributes"/>
 <rng:ref name="att.locatable.attributes"/>
 <rng:optional>
  <rng:attribute name="calendar">
   <rng:list>
    <rng:oneOrMore>
     <rng:ref name="teidata.pointer"/>
    </rng:oneOrMore>
   </rng:list>
  </rng:attribute>
 </rng:optional>
 <rng:attribute name="fromUnit">
  <rng:ref name="teidata.pointer"/>
 </rng:attribute>
 <rng:attribute name="toUnit">
  <rng:ref name="teidata.pointer"/>
 </rng:attribute>
 <rng:empty/>
</rng:element>
element conversion
{
   att.global.attributes,
   att.global.rendition.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   att.global.responsibility.attributes,
   att.global.source.attributes,
   att.datable.attributes,
   att.datable.w3c.attributes,
   att.datable.iso.attributes,
   att.datable.custom.attributes,
   att.formula.attributes,
   att.locatable.attributes,
   attribute calendar { list { teidata.pointer+ } }?,
   attribute fromUnit { teidata.pointer },
   attribute toUnit { teidata.pointer },
   empty
}