Attempt to provide some "clarity" about the UAPI .h files.

Not the correct wording at all, but something to start the conversation.
Lawyers like to have conversations :)

---
 COPYING |    4 ++++
 1 file changed, 4 insertions(+)

--- a/COPYING
+++ b/COPYING
@@ -11,6 +11,10 @@ With an explicit syscall exception, as s
 
 	LICENSES/exceptions/Linux-syscall-note
 
+The syscall exception only applies to the User API headers (UAPI) which are
+required to build user space applications which can interact with the Linux
+kernel.
+
 In addition, other licenses may also apply. Please see:
 
 	Documentation/process/license-rules.rst