The Expression property of the PropertyNameMetadata is used as a base for a Regex that is run against the property names of the object that is being serialized. Therefore, you should consider it a regex expression and set its value as in the following example:
- to match only the property "Width" - use the expression "^\b(Width)\b$", without the quotes.
- to match the "Width", "MinWidth" and "MaxWidth" - use the expression "Width", without the quotes.