--- a/xml/en/docs/http/ngx_http_api_module_head.xml
+++ b/xml/en/docs/http/ngx_http_api_module_head.xml
@@ -9,7 +9,7 @@
 <module name="Module ngx_http_api_module"
         link="/en/docs/http/ngx_http_api_module.html"
         lang="en"
-        rev="2">
+        rev="3">
 
 <section id="summary">
 
@@ -31,6 +31,15 @@ modules.
 </para>
 
 <para>
+When using the <literal>PATCH</literal> or <literal>POST</literal> methods,
+make sure that the payload does not exceed the
+<link doc="ngx_http_core_module.xml" id="client_body_buffer_size">buffer size</link>
+for reading the client request body, otherwise, the
+<http-status code="413" text="Request Entity Too Large"/>
+error may be returned.
+</para>
+
+<para>
 <note>
 This module is available as part of our
 <commercial_version>commercial subscription</commercial_version>.