If a datatype is standard, then it may have been originally specified as "restriction".
MrBayes introduced the datatype=restriction syntax for 01 symbols.
The restriction site datatype was added by MrBayes, It is supported by NCL, but you have to call this function to see if the matrix was specified as restriction site data (we did not add a facet to the DataTypesEnum to avoid the need to extend other code).
NCL reads this type as standard, but sets a flag. If the datatype is reported as Standard, then you can call WasRestrictionDataype to see if the datatype was declared "RESTRICTION"