OET Template - Limit-to-list

Problem (BF)

In TemplateDesigner for a Template (.OET)  on DV_TEXT element, you can set a ‘limit to list’ property. Which eventually tells either the valueSet is open/closed list. 
The question is how handle this with ADL/AOM2?
I was reluctant to support this, but looks like some Russian friends use this heavily and we have no way not to support it. ;(
TB response:

Well, 'limit to list' just means (if I understand right), that the terms provided are the exhaustive set of terms for that DV_CODED_TEXT. So that is the default situation in ADL (1.4 and 2). If you don't set this 'limit to list', what else is allowed? If it is text (i.e. DV_TEXT) then you can include a structure like:

        name ∈ {
            DV_CODED_TEXT[id79] ∈ {
                defining_code ∈ {[ac1]}
            DV_TEXT[id14] ∈ {
                value ∈ {/.+/}

But if it means 'allow other codes from this terminology', then we may need something else in ADL - something equivalent to this idea of non-exhaustive redefinition.

So if you can let me know what the required semantics are, I'll try to address it properly.