<sch:rule context="tei:*/@source"> <sch:let name="srcs" value="tokenize( normalize-space(.),' ')"/> <sch:report test="( parent::tei:classRef | parent::tei:dataRef | parent::tei:elementRef
| parent::tei:macroRef | parent::tei:moduleRef | parent::tei:schemaSpec
) and $srcs[2]"> When used on a schema description element (like <sch:value-of select="name(..)"/>), the @source attribute should have only 1 value. (This one has <sch:value-of select="count($srcs)"/>.) </sch:report> </sch:rule>
Note
The source attribute points to an external source. When used on an element describing a schema
component (classRef, dataRef, elementRef, macroRef, moduleRef, or schemaSpec), it identifies the source from which declarations for the components should be obtained.
On other elements it provides a pointer to the bibliographical source from which a
quotation or citation is drawn.
In either case, the location may be provided using any form of URI, for example an
absolute URI, a relative URI, a private scheme URI of the form tei:x.y.z, where x.y.z indicates the version number, e.g. tei:4.3.2 for TEI P5 release 4.3.2 or (as a special case) tei:current for whatever is the latest release, or a private scheme URI that is expanded to an
absolute URI as documented in a prefixDef.
When used on elements describing schema components, source should have only one value; when used on other elements multiple values are permitted.
Example
<p> <!-- ... --> As Willard McCarty (<bibl xml:id="mcc_2012">2012, p.2</bibl>) tells us, <quote source="#mcc_2012">‘Collaboration’ is a problematic and should be a contested term.</quote> <!-- ... --> </p>
<p> <!-- ... --> <quote source="#chicago_15_ed">Grammatical theories are in flux, and the more we learn, the less we seem to know.</quote> <!-- ... --> </p> <!-- ... --> <bibl xml:id="chicago_15_ed"> <title level="m">The Chicago Manual of Style</title>, <edition>15th edition</edition>. <pubPlace>Chicago</pubPlace>: <publisher>University of Chicago Press</publisher> (<date>2003</date>), <biblScope unit="page">p.147</biblScope>.