Agreed to changes edited in Raleigh meeting.

This is impossible to implement in many systems that limit the code units rather than the character.

Propose adding MaxCodeUnitCount Property in addition to MaxStringLength.
This would be implementable and unambiguous.

Added text to DataVariable description of MaxStringLength as follows:

The Property MaxStringLength indicates the maximum number of Unicode characters of a string value, however the number may be further limited by the way the server represents the characters.

After further review with Randy we concluded that a Server should only include these optional properties if it can provide a client with a maximum value.
the rational for this decision is as follows:
1) These properties are intended to provide a Client with server limitation information.
2) If a client can not depend on the values of these properties then they are of little or no use to the client.

Servers should only use these maximum properties if they have a maximum and can correctly define this maximum.

Part 5 also contains text describing these Properties which must be modified to the same description applied to Part 3

Update the text in 5.6.4 DataVariable to indicate that if present the MaxStringLength and maxByteStringLength properties provide the maximum.

Added a 3rd property, MaxCharacters, to make it clear when the limit is on characters rather than on bytes.

Agreed to changes edited in telecon.