2.1.868 Part 4 Section 3.14.5, definedName (Defined Name)
a. The standard does not specify the maximum length for @name.
Office limits the possible values of @name to be defined names as defined in Names ("[ECMA-376] Part 4 §18.104.22.168; Names").
b. In the standard the refersTo attribute uses the ST_Xstring type.
Office requires @referTo to be a valid formula that is restricted to cell references within the same external book.
c. The standard does not specify the range of the sheetId attribute.
Office restricts the sheetID attribute to a minimum value of greater than or equal to 0 and less than or equal to 65533.