Section 4.2 Text (String)
Change definition to "A Text value (also called a string value) is a "Character string" per [CharModel]" and add normative reference to:
[CharModel] Durst, et. al., "Character Model for the World Wide Web 1.0: Fundamentals", W3C (2005)
http://www.w3.org/TR/2005/REC-charmod-20050215/
Also add new paragraph:
Whether or not Unicode Normalization [UniNorm] is performed on formulas, formula results or user inputs is implementation-defined. Some functions defined in this Part are labeled as "normalization-sensitive", meaning that the results of the formula evaluation may differ depending on whether normalization occurs, and which normalization form is used. Mixing operands of different normalization forms in the same calculation is undefined.
Add informative reference:
[UniNorm] David, Mark and Martin Dürst, "Unicode Normalization Forms, Revision 25", The Unicode Consortium (2005)
http://www.unicode.org/reports/tr15/tr15-25.html
Finally for the following function definitions, add a sentence that says: "The results of this function may be normalization-sensitive. See section 4.2"
RIGHT, LEFT, MID, LEN, UNICODE