tabindexNumber 

tabindex attribute specifies the position of the current element
in the tabbing order for the current document. This value must be
a number between 0 and 32767. User agents should ignore leading zeros.

Simple Type Information

Used By

Attributes focus/@tabindex, object/@tabindex, select/@tabindex

Source 

<xs:simpleType name="tabindexNumber">
  <xs:annotation>
    <xs:documentation>tabindex attribute specifies the position of the current element in the tabbing order for the current document. This value must be a number between 0 and 32767. User agents should ignore leading zeros.</xs:documentation>
  </xs:annotation>
  <xs:restriction base="Number">
    <xs:minInclusive value="0"/>
    <xs:maxInclusive value="32767"/>
  </xs:restriction>
</xs:simpleType>