diff --git a/secure/precis/profile_test.go b/secure/precis/profile_test.go
index 253b2a0..916fc8b 100644
--- a/secure/precis/profile_test.go
+++ b/secure/precis/profile_test.go
@@ -100,6 +100,13 @@
 		{"Å", "å", true},
 		{"ﬀ", "ff", true}, // because of NFKC
 		{"ß", "sS", false},
+
+		// After applying the Nickname profile, \u00a8  becomes \u0020\u0308,
+		// however because the nickname profile is not idempotent, applying it again
+		// to \u0020\u0308 results in \u0308. This behavior is "correct", even if it
+		// is unexpected.
+		{"\u00a8", "\u0020\u0308", false},
+		{"\u0020\u0308", "\u0308", true},
 	}},
 }
 
diff --git a/secure/precis/profiles.go b/secure/precis/profiles.go
index 8b46d50..8601002 100644
--- a/secure/precis/profiles.go
+++ b/secure/precis/profiles.go
@@ -13,10 +13,19 @@
 )
 
 var (
-	Nickname              *Profile = nickname          // Implements the Nickname profile specified in RFC 7700.
-	UsernameCaseMapped    *Profile = usernameCaseMap   // Implements the UsernameCaseMapped profile specified in RFC 7613.
-	UsernameCasePreserved *Profile = usernameNoCaseMap // Implements the UsernameCasePreserved profile specified in RFC 7613.
-	OpaqueString          *Profile = opaquestring      // Implements the OpaqueString profile defined in RFC 7613 for passwords and other secure labels.
+	// Implements the Nickname profile specified in RFC 7700.
+	// The nickname profile is not idempotent and may need to be applied multiple
+	// times before being used for comparisons.
+	Nickname *Profile = nickname
+
+	// Implements the UsernameCaseMapped profile specified in RFC 7613.
+	UsernameCaseMapped *Profile = usernameCaseMap
+
+	// Implements the UsernameCasePreserved profile specified in RFC 7613.
+	UsernameCasePreserved *Profile = usernameNoCaseMap
+
+	// Implements the OpaqueString profile defined in RFC 7613 for passwords and other secure labels.
+	OpaqueString *Profile = opaquestring
 )
 
 var (