--- CBOR-XS/doc/stringref.pod	2018/04/25 06:37:12	1.5
+++ CBOR-XS/doc/stringref.pod	2018/04/30 11:24:17	1.6
@@ -190,6 +190,25 @@
 on top of every generic CBOR encoder/decoder (which might reorder entries
 in a map); they typically need to be integrated into their works.
 
+=head2 DESIGN RATIONALE
+
+The stringref tag was chosen to be short, without requiring standards
+action. The namespace tag is rare, so doesn't benefit from a short
+encoding as much.
+
+Implicit tagging/counting was chosen to support stream encoders. Having
+to tag strings first requires either multiple passes over the data (which
+might not be available, ruling out some encoders) or tagging more strings
+than needed (wasting space). Explicit tagging also isn't necessarily
+better even under optimal conditions, as the explicit tags waste space.
+
+Stream decoders are affected less by implicit tagging than encoders.
+
+The namespace tag was introduced for two reasons: first to allow embedding
+of CBOR strings into other CBOR strings, secondly for decoding efficiency
+- the decoder only has to expect stringref tags inside namespaces and
+therefore doesn't have to maintain extra state outside of them.
+
 =head1 EXAMPLES
 
 The array-of-maps from the rationale example would normally compress to a