SCTEST/SCTESTCD value not found in 'Subject Characteristic Test Name' non-extensible codelist

P21 v.2.1, CDISC-CT 2015-12-18, configuration SDTM 3.1.2 (PMDA).

I got errors that "EDLEVEL" and "Education Level" are not found in non-extensible codelists SCTESTCD/SCTEST.
However, if I look into the XML distribution of CDISC-CT-2015-12-18 it says that both codelist SCTESTCD and SCTEST ARE extensible (def:Extensible="Yes")

On the other hand, when I remove "MARRIED" as a valuelevel codelist entry in my define.xml, no error is generated. In that case, error CT2005 "Variable should be populated with terms from its CDISC controlled terminology codelist, when its value level condition is met" should be thrown. The system should then read my def:WhereClauseDef stating:
<def:WhereClauseDef OID="WC.SC.SCTESTCD.MARISTAT">
        <RangeCheck SoftHard="Soft" def:ItemOID="IT.SC.SCTESTCD" Comparator="EQ">
              <CheckValue>MARISTAT</CheckValue>
        </RangeCheck>
 </def:WhereClauseDef>

referenced by:

<ItemRef ItemOID="IT.SC.SCORRES.MARISTAT" OrderNumber="2" Mandatory="No">
          <def:WhereClauseRef WhereClauseOID="WC.SC.SCTESTCD.MARISTAT"/>
</ItemRef>

leading to the corresponding ItemDef:

<ItemDef OID="IT.SC.SCORRES.MARISTAT" Name="SC.MARISTAT" DataType="text" Length="17" SASFieldName="MARISTAT">
        <Description>
          <TranslatedText xml:lang="en">Marital Status</TranslatedText>
        </Description>
        <CodeListRef CodeListOID="CL.MARISTAT"/>
        ...
</ItemDef>

so when the system finds SCTESTCD=MARISTAT, it should apply the WhereClause leading to the statement that there is an associated valuelist CodeList containing a number of values. If "MARRIED" is not found in that codelist, the error CT2005 should be thrown.

Does P21 validator interprete the "WhereClause"s from the define.xml?