att.scoping provides attributes for selecting particular elements within a document by means of XPath.
Moduletei — The TEI Infrastructure
Memberscertainty precision respons
targetpoints at one or several elements or sets of elements by means of one or more data pointers, using the URI syntax.
Status Optional
Datatype 1–∞ occurrences of 

<rng:ref name="data.pointer"/>
separated by whitespace
Elizabeth went
to <persName xml:id="ESSEX">Essex</persName>
<certainty target="#ESSEXlocus="namedegree="0.6"/>

If more than one identifier is given, the implication is that all elements (or nodesets) are intended. The match attribute may also be used as a means of identifying groups of elements.

matchsupplies an arbitrary XPath expression using the syntax defined in Kay (ed.) (2007) which identifies a set of nodes, selected within the context identified by the target attribute if this is supplied, or within the context of the element bearing this attribute if it is not.
Status Optional

<gap reason="cancelled">
 <certainty match="@reasonlocus="valuecert="low"/>

The expression of certainty applies to the nodeset identified by the value of the target attribute, possibly modified additionally by the value of the match attribute. If neither attribute is present, the expression of certainty applies to the context of the certainty element itself, i.e. its parent element.

Note that the value of the target attribute may include an XPointer expression including an XPath expression (see 16.2.5 TEI XPointer Schemes).