improved texts for warning message and docs

python/core/auto_generated/qgsattributeeditorelement.sip.in

@@ -443,15 +443,15 @@ opening of the attribute form dialog when digitizing is completed.
 
     QVariant nmRelationId() const;
 %Docstring
-Determines the nmRelationId used for the many-to-many cardinality.
+Determines the relation id of the second relation involved in an N:M relation.
 
 .. versionadded:: 3.16
 %End
 
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );
 %Docstring
-Sets ``nmRelationId`` in a many-to-many cardinality.
+Sets ``nmRelationId`` for the relation id of the second relation involved in an N:M relation.
-If it's empty, then it's considered as a one-to-many relationship.
+If it's empty, then it's considered as a 1:M relationship.
 
 .. versionadded:: 3.16
 %End

python/gui/auto_generated/editorwidgets/qgsrelationwidgetwrapper.sip.in

@@ -132,15 +132,15 @@ opening of the attribute form dialog when digitizing is completed.
 
     QVariant nmRelationId() const;
 %Docstring
-Determines the nmRelationId used for the many-to-many cardinality.
+Determines the relation id of the second relation involved in an N:M relation.
 
 .. versionadded:: 3.16
 %End
 
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );
 %Docstring
-Sets ``nmRelationId`` in a many-to-many cardinality.
+Sets ``nmRelationId`` for the relation id of the second relation involved in an N:M relation.
-If it's empty, then it's considered as a one-to-many relationship
+If it's empty, then it's considered as a 1:M relationship.
 
 .. versionadded:: 3.16
 %End

python/gui/auto_generated/qgsrelationeditorwidget.sip.in

@@ -200,15 +200,15 @@ configured for this widget
 
     QVariant nmRelationId() const;
 %Docstring
-Determines the nmRelationId used for the many-to-many cardinality.
+Determines the relation id of the second relation involved in an N:M relation.
 
 .. versionadded:: 3.16
 %End
 
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );
 %Docstring
-Sets ``nmRelationId`` in a many-to-many cardinality.
+Sets ``nmRelationId`` for the relation id of the second relation involved in an N:M relation.
-If it's empty, then it's considered as a one-to-many relationship
+If it's empty, then it's considered as a 1:M relationship.
 
 .. versionadded:: 3.16
 %End

src/core/qgsattributeeditorelement.h

@@ -482,14 +482,14 @@ class CORE_EXPORT QgsAttributeEditorRelation : public QgsAttributeEditorElement
     void setForceSuppressFormPopup( bool forceSuppressFormPopup );
 
     /**
-     * Determines the nmRelationId used for the many-to-many cardinality.
+     * Determines the relation id of the second relation involved in an N:M relation.
      * \since QGIS 3.16
      */
     QVariant nmRelationId() const;
 
     /**
-     * Sets \a nmRelationId in a many-to-many cardinality.
+     * Sets \a nmRelationId for the relation id of the second relation involved in an N:M relation.
-     * If it's empty, then it's considered as a one-to-many relationship.
+     * If it's empty, then it's considered as a 1:M relationship.
      * \since QGIS 3.16
      */
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );

src/gui/editorwidgets/qgsrelationwidgetwrapper.h

@@ -122,14 +122,14 @@ class GUI_EXPORT QgsRelationWidgetWrapper : public QgsWidgetWrapper
     void setForceSuppressFormPopup( bool forceSuppressFormPopup );
 
     /**
-    * Determines the nmRelationId used for the many-to-many cardinality.
+     * Determines the relation id of the second relation involved in an N:M relation.
     * \since QGIS 3.16
     */
     QVariant nmRelationId() const;
 
     /**
-     * Sets \a nmRelationId in a many-to-many cardinality.
+     * Sets \a nmRelationId for the relation id of the second relation involved in an N:M relation.
-     * If it's empty, then it's considered as a one-to-many relationship
+     * If it's empty, then it's considered as a 1:M relationship.
      * \since QGIS 3.16
      */
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );

src/gui/qgsrelationeditorwidget.h

@@ -235,14 +235,14 @@ class GUI_EXPORT QgsRelationEditorWidget : public QgsCollapsibleGroupBox
     void setForceSuppressFormPopup( bool forceSuppressFormPopup );
 
     /**
-    * Determines the nmRelationId used for the many-to-many cardinality.
+    * Determines the relation id of the second relation involved in an N:M relation.
     * \since QGIS 3.16
     */
     QVariant nmRelationId() const;
 
     /**
-     * Sets \a nmRelationId in a many-to-many cardinality.
+     * Sets \a nmRelationId for the relation id of the second relation involved in an N:M relation.
-     * If it's empty, then it's considered as a one-to-many relationship
+     * If it's empty, then it's considered as a 1:M relationship.
      * \since QGIS 3.16
      */
     void setNmRelationId( const QVariant &nmRelationId = QVariant() );