diff --git a/v2:-Documentation.md b/v2:-Documentation.md
index 4e58637..88660e7 100644
--- a/v2:-Documentation.md
+++ b/v2:-Documentation.md
@@ -546,12 +546,12 @@ encode [<matcher>] <formats...> {
 
 ##### headers
 
-Manipulates HTTP response headers.
+Manipulates HTTP response headers. Can add, remove, set, or do substring replacements.
 
 ```
-headers [<matcher>] [[+|-]<field> [<value>]] {
-	[+][<field>] [<value>]
-	[-<field>]
+headers [<matcher>] [[+|-]<field> [<value|regexp>] [<replacement>]] {
+	[+]<field> [<value|regexp> [<replacement>]]
+	-<field>
 }
 ```
 
@@ -560,7 +560,7 @@ headers [<matcher>] [[+|-]<field> [<value>]] {
 Manipulates an HTTP request header.
 
 ```
-request_header [<matcher>] [[+|-]<field> [<value>]]
+request_header [<matcher>] [[+|-]<field> [<value|regexp>] [replacement]]
 ```
 
 ##### php_fastcgi
@@ -570,9 +570,9 @@ Proxies requests to one or more FastCGI backends specially configured for PHP ap
 ```
 # canonicalize URI trailing slash when index file present
 matcher indexFiles {
-	not {
-		path */
-	}
+    not {
+        path */
+    }
     file {
         try_files {path}/index.php
     }
@@ -629,6 +629,10 @@ reverse_proxy [<matcher>] [<upstreams...>] {
     unhealthy_status <status>
     unhealthy_latency <duration>
 
+	# header manipulation
+    header_up   [+|-]<field> [<value|regexp> [<replacement>]]
+    header_down [+|-]<field> [<value|regexp> [<replacement>]]
+
     # round trip
     transport <name> {
         ...