// ** Create a memo attribute ** MemoAttributeMetadata memoAttribute = new MemoAttributeMetadata { // Set base properties SchemaName = "new_memo", DisplayName = new Label("Sample Memo", 1033), RequiredLevel = new AttributeRequiredLevelManagedProperty(AttributeRequiredLevel.None), Description = new Label("Memo Attribute", 1033), // Set extended properties Format = StringFormat.TextArea, ImeMode = ImeMode.Disabled, MaxLength = 500 }; // Create the request. CreateAttributeRequest createAttributeRequest = new CreateAttributeRequest { EntityName = "EntityLogicalName", Attribute = memoAttribute }; // Execute the request. Get Response CreateAttributeResponse resp = (CreateAttributeResponse)_service.Execute(createAttributeRequest);