data.version

data.version defines the range of attribute values which may be used to specify a TEI version number.
Module tei — 1 The TEI Infrastructure
Used by
Element:
Declaration 

<rng:define name="data.version">
 <rng:data type="token">
  <rng:param name="pattern">[\d]+(\.[\d]+){0,2}</rng:param>
 </rng:data>
</rng:define>
data.version = token { pattern = "[\d]+(\.[\d]+){0,2}" }
Note
The pattern specified matches values defined by the Unicode consortium for its version number (reference). The version number contains digits and fullstop characters only. The first number supplied identifies the major version number. A second and third number, for minor and sub-minor version numbers, may also be supplied.