diff --git a/src/unpriv/f-st-ext.adoc b/src/unpriv/f-st-ext.adoc
index de2724dc3..5eb849283 100644
--- a/src/unpriv/f-st-ext.adoc
+++ b/src/unpriv/f-st-ext.adoc
@@ -193,6 +193,12 @@ quiet bit. For single-precision floating-point, this corresponds to the pattern
 (((NaN, generation)))
 (((NaN, propagation)))
 
+[NOTE]
+====
+The canonical NaN as defined here is unrelated to the definition of
+canonical encodings in IEEE 754-2008 for decimal interchange formats.
+====
+'''
 [NOTE]
 ====
 We considered propagating NaN payloads, as is recommended by IEEE