diff --git a/cds/cdl.md b/cds/cdl.md
index 48cad8ff5..0f117c6ed 100644
--- a/cds/cdl.md
+++ b/cds/cdl.md
@@ -1154,7 +1154,7 @@ entity P_Authors as projection on Authors {
 In this example, in addition to `books` projection `P_Authors` has a new association `availableBooks`
 that points only to those books where `stock > 0`.
 
-If the filter condition effectively reduces the cardinality of the association
+If the filter condition effectively reduces the cardinality of the association (or composition)
 to one, you should make this explicit in the filter by adding a `1:` before the condition:
 
 ```cds
@@ -1164,6 +1164,12 @@ entity P_Employees as projection on Employees {
 }
 ```
 
+::: warning `:1` doesn't itself reduce the cardinality
+The `:1` syntax itself has no effect on the cardinality. It is only an information by the developer
+that the specified condition reduces the cardinality of the association or composition to one.
+:::
+
+
 Filters usually are provided only for to-many associations, which usually are unmanaged.
 Thus publishing with a filter is almost exclusively used for unmanaged associations.
 Nevertheless you can also publish a managed association with a filter. This will automatically
diff --git a/cds/cql.md b/cds/cql.md
index 3e2abae87..dfe91df2b 100644
--- a/cds/cql.md
+++ b/cds/cql.md
@@ -354,6 +354,11 @@ If an infix filter effectively reduces the cardinality of a *to-many* associatio
 SELECT name, books[1: favorite=true].title from Authors
 ```
 
+::: warning `:1` has no effect on result set
+The `:1` syntax in the filter has no effect on the result. It is only an information by the developer
+that the specified condition reduces the result to a single entry.
+:::
+
 ### Exists Predicate
 
 Use a filtered path expression to test if any element of the associated collection matches the given filter: