contextual statements in rules

In chapter 6.4.2 of the OpenClinica documentation it's written:

Now OpenClinica utilizes what is known as contextual statements, meaning as in the examples above you can put ITEM_OID and OpenClinica will automatically complete the statement so to make it legal. Let’s use an example

<Target Context="OC_RULES_V1">SED_OID[ALL].CRF_OID.GROUP_OID.ITEM_OID</Target> … <Expression> ITEM_OID eq 50</Expression>

What will actually happen here when this expression is being evaluated is that ITEM_OID will be substituted by

SED_OID[ordinal].CRF_OID.GROUP_OID.ITEM_OID

So I tried to setup this:

<RuleImport>

  <RuleAssignment>
    <Target Context="OC_RULES_V1">MyEventOID.MyFormOID.MyGroupOID.MyDateFieldOID</Target>
    <RuleRef OID="R1">
      ...
    </RuleRef>
  </RuleAssignment>

  <RuleDef OID="R1" Name="R1">
    <Description>Test date not being in the future</Description>
    <Expression>ITEM_OID gt _CURRENT_DATE</Expression>
  </RuleDef>

</RuleImport>

When trying to import this XML file OpenClinica does reject it with the following error messages:

Invalid Rules

Rule OID	Rule Name	Description	Potential Import Errors
R1	R1	Test date not being in the future	OCRERR_0013 : The following : ITEM_OID is not valid.

Invalid Rule Assignments

Target	Rules	Errors
MyEventOID.MyFormOID.MyGroupOID.MyDateFieldOID	RuleOID  ActionMessage  Info	OCRERR_0025: The Rule you are trying to reference does not exist or is invalid. OCRERR_0027: The contextual expression in one of the Rules does not validate against the target expression in the current Rule assignment.

The field is of type 'date'.

Do I misunderstand the documentation or what am I doing wrong here? Finally I would like to use the one rule to check multiple date fields against future date which will only be possible if ITEM_OID can be used as placeholder for the actual item.

Regards

Franz