diff --git a/docs/basics.md b/docs/basics.md
index 170f5a210..9635dd3e7 100644
--- a/docs/basics.md
+++ b/docs/basics.md
@@ -236,7 +236,8 @@ The following rules are both `Matchers` and `Modifiers`, so the `Matcher` portio
 #### Priorities
 
 By default, routes will be sorted (in descending order) using rules length (to avoid path overlap):
-`PathPrefix:/foo;Host:foo.com` (length == 28) will be matched before `PathPrefixStrip:/foobar` (length == 23) will be matched before `PathPrefix:/foo,/bar` (length == 20).
+- `PathPrefix:/foo;Host:foo.com` (length == 28) will be matched before `PathPrefixStrip:/foobar` (length == 23) will be matched before `PathPrefix:/foo,/bar` (length == 20).  
+- A priority value of 0 will be ignored, so the default value will be calculated (rules length).
 
 You can customize priority by frontend. The priority value override the rule length during sorting: