diff --git a/Doc/Manual/Extending.html b/Doc/Manual/Extending.html
index c6e006033..ff666791c 100644
--- a/Doc/Manual/Extending.html
+++ b/Doc/Manual/Extending.html
@@ -2754,15 +2754,16 @@ int Python::top(Node *n) {
 
 
 <p>
-Within SWIG wrappers, there are four main sections. These are (in order)
+Within SWIG wrappers, there are five main sections. These are (in order)
 </p>
 
 <ul>
-<li>runtime: This section has most of the common SWIG runtime code
-<li>header: This section holds declarations and inclusions from the .i file
-<li>wrapper: This section holds all the wrappering code
+<li>begin: This section is a placeholder for users to put code at the beginning of the C/C++ wrapper file.
+<li>runtime: This section has most of the common SWIG runtime code.
+<li>header: This section holds declarations and inclusions from the .i file.
+<li>wrapper: This section holds all the wrappering code.
 <li>init: This section holds the module initalisation function
-(the entry point for the interpreter)
+(the entry point for the interpreter).
 </ul>
 <p>
 Different parts of the SWIG code will fill different sections,
diff --git a/Doc/Manual/SWIG.html b/Doc/Manual/SWIG.html
index fd510f2a4..bcfcc60f5 100644
--- a/Doc/Manual/SWIG.html
+++ b/Doc/Manual/SWIG.html
@@ -3034,14 +3034,15 @@ output of SWIG is structured first.</p>
 
 
 <p>
-When SWIG creates its output file, it is broken up into four sections
+When SWIG creates its output file, it is broken up into five sections
 corresponding to runtime code, headers, wrapper functions, and module
 initialization code (in that order).   
 </p>
 
 <ul>
 <li><b>Begin section</b>.  <br>
-A placeholder to put code at the beginning of the C/C++ wrapper file.
+A placeholder for users to put code at the beginning of the C/C++ wrapper file.
+This is most often used to define preprocessor macros that are used in later sections.
 </li>
 
 <li><b>Runtime code</b>.  <br>