Different kind of properties can be defined for samples in the region config file SampleMetadataSchema.xml.
They can have different value types like the predefined string, double or dataTime but also custom value types.
With custom value types it is possible to define a list of restricted values the properties can have.
An example configuration can be seen below where the different properties are defined in SampleProperties.csv and the custom value type "SOURCE" in Bron.csv. By using %<column>% there can be referred to the content of the columns in the csv file.
In SampleProperties.csv (located in MaplayerFiles config directory) shown below the properties "EMP_NR_A", "EXT_REF", "SMP_NAME" and "COST_CODE" are sample properties which are of value type "TEXT" that is defined as string with no other restrictions.
The property "BRON" however has the custom value type "SOURCE" which is defined as an enumeration in the file Bron.csv (located in MaplayerFiles config directory). This means the values of the property "BRON" can only have the values "Visdata_Waternet_2006-2012 V4" or "MACFT2010LIJN"