softwarepub · zyzzyxdonta · Dec 18, 2025 · Dec 18, 2025
diff --git a/docs/appendices/ontology.md b/docs/appendices/ontology.md
@@ -88,7 +88,7 @@ sc:AllowedOuterType a owl:Class ;
     rdfs:label "Allowed Outer Type"@en ;
     rdfs:comment """The set of container types that may be used as outer types for parameters.
                     This includes scalar (single value), ordered lists, and unordered bags."""@en ;
-    owl:oneOf ( sc:Scalar rdf:List rdf:Bag ) ;
+    owl:oneOf ( sc:Scalar rdf:List ) ;
     rdfs:isDefinedBy <https://schema.software-metadata.pub/software-card/2025-01/#> .
 
 # Class Definition with cardinality restrictions
@@ -143,7 +143,7 @@ sc:parameterOuterType a owl:ObjectProperty ;
     rdfs:label "parameter outer type"@en ;
     rdfs:comment """Specifies the container/cardinality type of the parameter value.
                     Determines whether the parameter represents a single value (sc:Scalar),
-                    an ordered collection (rdf:List), or an unordered collection (rdf:Bag)."""@en ;
+                    or a list of values (rdf:List)."""@en ;
     rdfs:domain sc:Parameter ;
     rdfs:range sc:AllowedOuterType ;
     rdfs:isDefinedBy <https://schema.software-metadata.pub/software-card/2025-01/#> .
@@ -171,7 +171,7 @@ sc:parameterDefaultValue a rdf:Property ;
                     parameter becomes required and must be provided in the configuration file.
                     When present, the default value must match the parameter's declared outer
                     and inner types. For scalar parameters, this is a single literal or resource.
-                    For list or bag parameters, this is an rdf:List or rdf:Bag."""@en ;
+                    For list parameters, this is an rdf:List."""@en ;
     rdfs:domain sc:Parameter ;
     rdfs:isDefinedBy <https://schema.software-metadata.pub/software-card/2025-01/#> .
 
@@ -241,8 +241,8 @@ sc:ParameterShape a sh:NodeShape ;
         sh:description "The container/cardinality type of the parameter."@en ;
         sh:minCount 1 ;
         sh:maxCount 1 ;
-        sh:in ( sc:Scalar rdf:List rdf:Bag ) ;
-        sh:message "Parameter must have exactly one outer type: sc:Scalar, rdf:List, or rdf:Bag."@en ;
+        sh:in ( sc:Scalar rdf:List ) ;
+        sh:message "Parameter must have exactly one outer type: sc:Scalar, or rdf:List."@en ;
     ] ;
 
     # Must have exactly one inner type from allowed set

diff --git a/docs/specification/parameterization.md b/docs/specification/parameterization.md
@@ -97,8 +97,8 @@ We mention dates as an example here but disallow them later.
 This separation allows the framework to correctly handle configurations like:
 
 - A minimum character requirement for descriptions (outer: `sc:Scalar`, inner: `xsd:int`)
-- A list of license URIs (outer: `rdf:List`, inner: `xsd:anyURI`)
-- A set of organization names (outer: `rdf:Bag`, inner: `xsd:string`)
+- A selection of license URIs (outer: `rdf:List`, inner: `xsd:anyURI`)
+- A list of organization names (outer: `rdf:List`, inner: `xsd:string`)
 
 
 ## `sc:parameterInnerType`
@@ -159,13 +159,13 @@ The outer type MUST be present and MUST specify how values are structured.
 
 These types MUST be supported by implementations:
 
-| Outer Type  | Meaning            | Use When                                     | Example                                    |
-| ----------- | ------------------ | -------------------------------------------- | ------------------------------------------ |
-| `sc:Scalar` | Single value       | Only one value is needed                     | Minimum description length, a boolean flag |
-| `rdf:List`  | Ordered sequence   | Order matters and multiple values are needed | Priority-ordered list of licenses          |
-| `rdf:Bag`   | Unordered sequence | Order does not matter for multiple values    | List of software dependencies              |
+| Outer Type  | Meaning                                       | Use When                   | Examples                                                         |
+| ----------- | --------------------------------------------- | -------------------------- | ---------------------------------------------------------------- |
+| `sc:Scalar` | Single value                                  | Only one value is needed   | Minimum text length, a boolean flag, a single email address, ... |
+| `rdf:List`  | Ordered and unordered sequences, enumerations | Multiple values are needed | A selection of allowed licenses, a list of persons, ...          |
 
-Ohter RDF collection types (like `rdf:Seq`, `rdf:Alt`) MAY be supported by a validation implementation.
+RDF container types (`rdf:Alt`, `rdf:Bag`, `rdf:Seq`) MAY be supported by validation implementations.
+However, these types are not supported by SHACL which means conversion has to be applied.
 
 ## `sc:parameterConfigKey`
 
@@ -323,18 +323,3 @@ scex:requiredKeywords a sc:Parameter ;
     sc:parameterConfigKey "required_keywords" ;
     sc:parameterDefaultValue ( "research-software" "open-source" ) .
 ```
-
-Configuration:
-```toml
-[policies.keywords.parameters]
-required_keywords = ["fair-software", "reproducible-research", "scientific-computing"]
-```
-
-**Bag of Strings (Unordered Collection):**
-```turtle
-scex:allowedLanguages a sc:Parameter ;
-    sc:parameterOuterType rdf:Bag ;
-    sc:parameterInnerType xsd:string ;
-    sc:parameterConfigKey "allowed_programming_languages" ;
-    sc:parameterDefaultValue ( "Python" "Java" "C++" ) .
-```
diff --git a/docs/specification/validation.md b/docs/specification/validation.md
@@ -90,8 +90,7 @@ Implementations MUST validate that configured parameter values match the declare
 
 1. **Outer Type Validation:**
    - `sc:Scalar`: parameters MUST receive a single value (not an array/list)
-   - `rdf:List`: parameters MUST receive an (ordered) array/list of values
-   - `rdf:Bag`: parameters MUST receive an (unorderd) array/list of values
+   - `rdf:List`: parameters MUST receive an array/list of values
 
 2. **Inner Type Validation:**
    - Values MUST be compatible with the declared XSD datatype

diff --git a/src/software_card_policies/data_model.py b/src/software_card_policies/data_model.py
@@ -7,6 +7,7 @@
 from enum import Enum
 from functools import reduce
 from pathlib import Path
+from types import NoneType
 from typing import Any, Dict, List, Tuple
 
 from pyshacl import validate
@@ -146,9 +147,6 @@ def from_graph(cls, reference: URIRef, graph: Graph):
 _ALLOWED_OUTER_TYPES = (
     SC.Scalar,
     RDF.List,
-    RDF.Seq,
-    RDF.Bag,
-    RDF.Alt,
 )
 
 _ALLOWED_INNER_TYPES = (
@@ -172,11 +170,10 @@ def read_rdf_resource(source: Path | str) -> Graph:
     return graph
 
 
-def _create_rdf_list_parameter(
+def _create_list_parameter(
     parameter: Parameter, graph: Graph, config_parameter: Any
 ) -> Node:
     assert parameter.outer_type == RDF.List
-    # assert (parameter.default_value, RDF.type, RDF.List) in graph
     assert (parameter.default_value, RDF.first, None) in graph
     assert (parameter.default_value, RDF.rest, None) in graph
 
@@ -190,12 +187,11 @@ def _create_rdf_list_parameter(
     ).uri
 
 
-def _create_sc_scalar_parameter(
+def _create_scalar_parameter(
     parameter: Parameter, graph: Graph, config_parameter: Any
 ) -> Node:
     assert parameter.outer_type == SC.Scalar
-
-    assert isinstance(config_parameter, (str, int, float, type(None)))
+    assert isinstance(config_parameter, (str, int, float, NoneType))
 
     if config_parameter:
         return Literal(config_parameter)
@@ -228,17 +224,10 @@ def parameterize_graph(graph: Graph, config_parameters: Dict[str, Any]) -> Graph
             )
 
         if parameter.outer_type == SC.Scalar:
-            o = _create_sc_scalar_parameter(parameter, graph, config_parameter)
-
-        elif parameter.outer_type == RDF.List:
-            o = _create_rdf_list_parameter(parameter, graph, config_parameter)
+            o = _create_scalar_parameter(parameter, graph, config_parameter)
 
         else:
-            raise NotImplementedError(
-                f"Parameter '{parameter.uri}' has outer type "
-                f"'{parameter.outer_type}', the handling of which "
-                "is currently not implemented"
-            )
+            o = _create_list_parameter(parameter, graph, config_parameter)
 
         # Add replacements for all occurences of the parameter. Again, extract
         # occurences before modifying the graph!