--- a/relpipe-data/principles.xml	Tue Nov 27 17:03:54 2018 +0100
+++ b/relpipe-data/principles.xml	Tue Nov 27 17:12:12 2018 +0100
@@ -216,6 +216,13 @@
 		</p>
 		
 		
+		<h2>Be exact and reliable</h2>
+		
+		<p>
+			<m:name/> should convey data without corrupting or waywardly modifying them.
+			Implementation details (e.g. how values are encoded in the stream) should not affect transferred data and the user.
+		</p>
+		
 		<h2>Fail-fast, be strict</h2>
 		
 		<p>