+# - COMPAT=/DNO_HTMLHELP (Windows only)
+# Disables PuTTY's use of <htmlhelp.h>, which is not available
+# with some development environments. The resulting binary
+# will only look for an old-style WinHelp file (.HLP/.CNT), and
+# will ignore any .CHM file.
+#
+# Note that this definition is always enabled in the Cygwin
+# build, since at the time of writing this <htmlhelp.h> is
+# known not to be available in Cygwin (although you can use
+# the htmlhelp.h supplied with HTML Help Workshop).
+#
+# - RCFL=/DNO_MANIFESTS (Windows only)
+# Disables inclusion of XML application manifests in the PuTTY
+# binaries. This may be necessary to build for 64-bit Windows;
+# the manifests are only included to use the XP GUI style on
+# Windows XP, and the architecture tags are a lie on 64-bit.
+#
+# - COMPAT=/DNO_IPV6
+# Disables PuTTY's ability to make IPv6 connections, enabling
+# it to compile under development environments which do not
+# support IPv6 in their header files.
+#
+# - COMPAT=/DNO_GSSAPI
+# Disables PuTTY's ability to use GSSAPI functions for
+# authentication and key exchange.
+#
+# - COMPAT=/DSTATIC_GSSAPI
+# Causes PuTTY to try to link statically against the GSSAPI
+# library instead of the default of doing it at run time.
+#
+# - COMPAT=/DMSVC4 (Windows only)