Document nonResponsibilities on Bounded Contexts

_docs/language-reference/bounded-context.md

@@ -16,6 +16,7 @@ BoundedContext CustomerManagementContext implements CustomerManagementDomain {
   domainVisionStatement = "The customer management context is responsible for ..."
   implementationTechnology = "Java, JEE Application"
   responsibilities = "Customers", "Addresses"
+  nonResponsibilities = "Policies", "Debt collection"
   knowledgeLevel = CONCRETE
 
   Module addresses {
@@ -98,6 +99,20 @@ The _implementationTechnology_ attribute allows you to add information about how
 ### Responsibility Layers
 With the _responsibilities_ keyword you are allowed to specify the responsibilities of the bounded context, according to the DDD Responsibility Layers pattern. See [responsibility layers](/docs/responsibility-layers/).
 
+### Non-Responsibilities
+With the _nonResponsibilities_ keyword you can state explicitly what the bounded context is **not** responsible for. Like _responsibilities_, the attribute takes a comma-separated list of strings:
+
+```cml
+BoundedContext TicketSales implements FareSales {
+  responsibilities = "Selling fare products", "Refunds"
+  nonResponsibilities = "Gate validation", "Support cases"
+}
+```
+
+Stating what is out of scope makes the boundary of a context explicit. This helps people as well as coding agents that read your model: they should not implement something in a context that the model explicitly excludes.
+
+When two bounded contexts are merged with the [Merge Bounded Contexts](/docs/ar-merge-bounded-contexts/) refactoring, the _nonResponsibilities_ lists are merged as well. Entries that are a responsibility of the merged context are removed.
+
 ### Knowledge Level
 With the _knowledgeLevel_ attribute you define the knowledge level of the bounded context which can be one of the following two:
  * CONCRETE

_docs/language-reference/responsibility-layers.md

@@ -6,7 +6,7 @@ permalink: /docs/responsibility-layers/
 The Responsibility Layers pattern from the ["blue book"](https://www.amazon.com/Domain-Driven-Design-Tackling-Complexity-Software/dp/0321125215) can be used on bounded contexts and aggregates to specify their responsibilities.
 
 ## Syntax
-The responsibilities can simply be defined with the keyword/attribute _responsibilities_ and a list of responsibilities (as strings):
+The responsibilities can simply be defined with the keyword/attribute _responsibilities_ and a list of responsibilities (as strings). On bounded contexts, you can additionally declare what the context is **not** responsible for with the _nonResponsibilities_ keyword (see [Bounded Context](/docs/bounded-context/#non-responsibilities)):
 
 ```cml
 BoundedContext CustomerManagementContext implements CustomerManagementDomain {