diff --git a/doc/public/tmpl/cairo-ft.sgml b/doc/public/tmpl/cairo-ft.sgml
index 0aac48296..68a3fd436 100644
--- a/doc/public/tmpl/cairo-ft.sgml
+++ b/doc/public/tmpl/cairo-ft.sgml
@@ -22,7 +22,8 @@ systems, but can be used on other platforms too.
-
+Defined if the FreeType font backend is available.
+This macro can be used to conditionally compile backend-specific code.
diff --git a/doc/public/tmpl/cairo-quartz-fonts.sgml b/doc/public/tmpl/cairo-quartz-fonts.sgml
index 3e7cd4d1c..0c6a73f16 100644
--- a/doc/public/tmpl/cairo-quartz-fonts.sgml
+++ b/doc/public/tmpl/cairo-quartz-fonts.sgml
@@ -23,7 +23,8 @@ implementation of the font backend methods.
-
+Defined if the Quartz font backend is available.
+This macro can be used to conditionally compile backend-specific code.
diff --git a/doc/public/tmpl/cairo-quartz.sgml b/doc/public/tmpl/cairo-quartz.sgml
index 78fe8de7e..bd3d76814 100644
--- a/doc/public/tmpl/cairo-quartz.sgml
+++ b/doc/public/tmpl/cairo-quartz.sgml
@@ -22,7 +22,8 @@ Apple OS X Quartz rendering system.
-
+Defined if the Quartz surface backend is available.
+This macro can be used to conditionally compile backend-specific code.
diff --git a/doc/public/tmpl/cairo-xlib.sgml b/doc/public/tmpl/cairo-xlib.sgml
index 9e33a174e..446d4a682 100644
--- a/doc/public/tmpl/cairo-xlib.sgml
+++ b/doc/public/tmpl/cairo-xlib.sgml
@@ -26,7 +26,8 @@ if it is available.
-
+Defined if the Xlib surface backend is available.
+This macro can be used to conditionally compile backend-specific code.