Update description for NULL_IF

Author: Lucky-Wang16

articles/data-factory/connector-snowflake.md

@@ -270,7 +270,7 @@ To copy data from Snowflake, the following properties are supported in the Copy
 | type | The type of export command, set to **SnowflakeExportCopyCommand**. | Yes |
 | storageIntegration | Specify the name of your storage integration that you created in the Snowflake. For the prerequisite steps of using the storage integration, see [Configuring a Snowflake storage integration](https://docs.snowflake.com/en/user-guide/data-load-azure-config#option-1-configuring-a-snowflake-storage-integration). | No |
 | additionalCopyOptions | Additional copy options, provided as a dictionary of key-value pairs. Examples: MAX_FILE_SIZE, OVERWRITE. For more information, see [Snowflake Copy Options](https://docs.snowflake.com/en/sql-reference/sql/copy-into-location.html#copy-options-copyoptions). | No |
-| additionalFormatOptions | Additional file format options that are provided to COPY command as a dictionary of key-value pairs. Examples: DATE_FORMAT, TIME_FORMAT, TIMESTAMP_FORMAT, NULL_IF. For more information, see [Snowflake Format Type Options](https://docs.snowflake.com/en/sql-reference/sql/copy-into-location.html#format-type-options-formattypeoptions). | No |
+| additionalFormatOptions | Additional file format options that are provided to COPY command as a dictionary of key-value pairs. Examples: DATE_FORMAT, TIME_FORMAT, TIMESTAMP_FORMAT, NULL_IF. For more information, see [Snowflake Format Type Options](https://docs.snowflake.com/en/sql-reference/sql/copy-into-location.html#format-type-options-formattypeoptions). <br/>When you select NULL_IF, the NULL value in the data will be converted to a specified value. If the value is not specified, it uses the default `NULL`. Additionally, the empty string in the data will be converted to a blank field. | No |
 
 >[!Note]
 > Make sure you have permission to execute the following command and access the schema *INFORMATION_SCHEMA* and the table *COLUMNS*.