3 files changed, 10 insertions, 7 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index 5c0376c55e32..63e9bf23ccc1 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -208,10 +208,19 @@ options 	MUTEX_PROFILING
 #
 # Implement system calls compatible with 4.3BSD and older versions of
 # FreeBSD.  You probably do NOT want to remove this as much current code
-# still relies on the 4.3 emulation.
+# still relies on the 4.3 emulation.  Note that some architectures that
+# are supported by FreeBSD do not include support for certain important
+# aspects of this compatibility option, namely those related to the
+# signal delivery mechanism.
 #
 options 	COMPAT_43
 
+#
+# Be compatible with SunOS.  The COMPAT_43 option above pulls in most
+# (all?) of the changes that this option turns on.
+#
+options 	COMPAT_SUNOS
+
 # Enable FreeBSD4 compatibility syscalls
 options 	COMPAT_FREEBSD4
 
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index 1ccb2d1b0b1e..fd42e4508641 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -1091,6 +1091,3 @@ options 	TIMER_FREQ=((14318182+6)/12)
 options 	VM_KMEM_SIZE
 options 	VM_KMEM_SIZE_MAX
 options 	VM_KMEM_SIZE_SCALE
-
-# Yet more undocumented options for linting.
-options 	COMPAT_SUNOS
diff --git a/sys/pc98/conf/NOTES b/sys/pc98/conf/NOTES
index ebee5793ff77..9d702c3beef9 100644
--- a/sys/pc98/conf/NOTES
+++ b/sys/pc98/conf/NOTES
@@ -940,9 +940,6 @@ options 	VM_KMEM_SIZE
 options 	VM_KMEM_SIZE_MAX
 options 	VM_KMEM_SIZE_SCALE
 
-# Yet more undocumented options for linting.
-options 	COMPAT_SUNOS
-
 
 #####################################################################
 # Devices we don't want to deal with