diff --git a/documentation20/cn/02.getting-started/02.taosdemo/docs.md b/documentation20/cn/02.getting-started/02.taosdemo/docs.md
index fee6708d3a51fa71fed64e31ade72a8dac05b259..3f91dbb35130a2ff78e5ef23219b79433af33ce3 100644
--- a/documentation20/cn/02.getting-started/02.taosdemo/docs.md
+++ b/documentation20/cn/02.getting-started/02.taosdemo/docs.md
@@ -145,7 +145,7 @@ insert delay, avg:       8.31ms, max:     860.12ms, min:       2.00ms
 ```
 $ taosdemo --help
 
--f, --file=FILE The meta file to the execution procedure.
+-f, --file=FILE The meta file to the execution procedure. Currently, we support standard UTF-8 (without BOM) encoded files only.
 -u, --user=USER The user name to use when connecting to the server.
 -p, --password The password to use when connecting to the server.
 -c, --config-dir=CONFIG_DIR Configuration directory.
@@ -442,7 +442,7 @@ TDengine是涛思数据专为物联网、车联网、工业互联网、IT运维
 taosdemo支持两种配置参数的模式，一种是命令行参数，一种是使用json格式的配置文件。
 一、命令行参数
 
--f：指定taosdemo所需参数的meta文件。当使用该参数时，其他所有命令行参数都失效。可选项，缺省是NULL。
+-f：指定taosdemo所需参数的meta文件。当使用该参数时，其他所有命令行参数都失效。可选项，缺省是NULL。目前仅支持不含 BOM（byte-order mark）的标准 UTF-8 编码文件。
 
 -u： 用户名。可选项，缺省是“root“。
 
diff --git a/documentation20/en/02.getting-started/02.taosdemo/docs.md b/documentation20/en/02.getting-started/02.taosdemo/docs.md
index cceebf44fc75bf56128f52aa7729a3eb1f03e565..318c4d09581672b317f487477e655bdb5bd49d13 100644
--- a/documentation20/en/02.getting-started/02.taosdemo/docs.md
+++ b/documentation20/en/02.getting-started/02.taosdemo/docs.md
@@ -154,7 +154,7 @@ The complete list of taosdemo command-line arguments can be displayed via taosde
 ```
 $ taosdemo --help
 
--f, --file=FILE The meta file to the execution procedure.
+-f, --file=FILE The meta file to the execution procedure. Currently, we support standard UTF-8 (without BOM) encoded files only.
 -u, --user=USER The user name to use when connecting to the server.
 -p, --password The password to use when connecting to the server.
 -c, --config-dir=CONFIG_DIR Configuration directory.