--- /src/winsup/doc/how-programming.texinfo	2003-02-13 15:20:32.000000000 +0100
+++ /src/winsup/doc/how-programming.texinfo-Hannu	2003-10-16 20:22:24.000000000 +0200
@@ -558,7 +558,7 @@ If your scripts are in the current direc
 you would need to add /bin/sh in front of each and every shell script
 invoked in your Makefiles.
 
-@subsection What preprocessor do I need to know about?
+@subsection What preprocessor symbols do I need to know about?
 
 We use _WIN32 to signify access to the Win32 API and __CYGWIN__ for
 access to the Cygwin environment provided by the dll.
@@ -574,6 +574,17 @@ Unix emulation environment and defining 
 which think that they have to make special concessions for a Windows
 environment which Cygwin handles automatically.
 
+Note that using -mno-cygwin replaces __CYGWIN__ with __MINGW32__ as to
+tell which compiler (or settings) you're running.
+Check this out in detail by running e.g.
+       $ gcc <option> -dM -E -xc /dev/null >gcc_<option>.txt
+with each <option>. Then use the diff and grep utilities to check
+what the difference is.
+Relevant <option> keywords;
+ -mno-cygwin
+ -mwin32
+ nothing (i.e. remove <option> and use the default WRT this).
+
 @subsection How should I port my Unix GUI to Windows?
 
 There are two basic strategies for porting Unix GUIs to Windows.