diff --git a/src/docs/markdown/caddyfile/concepts.md b/src/docs/markdown/caddyfile/concepts.md
index 767d489..f16d690 100644
--- a/src/docs/markdown/caddyfile/concepts.md
+++ b/src/docs/markdown/caddyfile/concepts.md
@@ -273,6 +273,15 @@ To match on anything other than a path, define a **named matcher** and refer to
 reverse_proxy @post localhost:9000
 ```
 
+To match using capture groups use a named matcher:
+
+```
+@ows {
+    path_regexp map_file ^/ows/(.*)
+}
+
+redir @ows /index.html?{query}&map=/io/data/{http.regexp.map_file.1}.qgs
+```
 
 
 ## Placeholders
@@ -356,4 +365,4 @@ If present, it must be the very first block in the config.
 
 It is used to set options that apply globally, or not to any one site in particular. Inside, only global options can be set; you cannot use regular site directives in them.
 
-[Learn more](/docs/caddyfile/options) about the global options block.
\ No newline at end of file
+[Learn more](/docs/caddyfile/options) about the global options block.