the type of the variable value. The attribute valueType can have one of the
following values:
- "boolean" - boolean type values are TRUE or FALSE
- "string"
- string type values are alphanumeric
- "integer" (D) - integer type values are
numeric and contain no decimal point
- "real" - real type values are numeric and
contain a decimal point
- "set-string", "set-real", or "set-integer" - set type
values represent an unordered list of like value types: string, real, or
integer