2.1.1087 Part 1 Section 18.18.47, ST_NumFmtId (Number Format Id)
a. The standard states that the values of the ST_NumFmtId simple type are defined by the XML Schema unsignedInt datatype.
-
Office restricts the values of this attribute to be at most 65535.
b. The standard does not restrict the values of instances of the ST_NumFmtId simple type.
-
Office requires the first instance of this type in any sequence to be equal to zero. This instance specifies the default style.