diff --git a/docs/en/07-develop/09-udf.md b/docs/en/07-develop/09-udf.md
index f8170d0d63..deb9c4cdb5 100644
--- a/docs/en/07-develop/09-udf.md
+++ b/docs/en/07-develop/09-udf.md
@@ -102,7 +102,7 @@ Replace `aggfn` with the name of your function.
 
 ## Interface Functions
 
-There are strict naming conventions for interface functions. The names of the start, finish, init, and destroy interfaces must be <udf-name>_start, <udf-name>_finish, <udf-name>_init, and <udf-name>_destroy, respectively. Replace `scalarfn`, `aggfn`, and `udf` with the name of your user-defined function.
+There are strict naming conventions for interface functions. The names of the start, finish, init, and destroy interfaces must be <udf-name\>_start, <udf-name\>_finish, <udf-name\>_init, and <udf-name\>_destroy, respectively. Replace `scalarfn`, `aggfn`, and `udf` with the name of your user-defined function.
 
 Interface functions return a value that indicates whether the operation was successful. If an operation fails, the interface function returns an error code. Otherwise, it returns TSDB_CODE_SUCCESS. The error codes are defined in `taoserror.h` and in the common API error codes in `taos.h`. For example, TSDB_CODE_UDF_INVALID_INPUT indicates invalid input. TSDB_CODE_OUT_OF_MEMORY indicates insufficient memory.