diff --git a/doc/pyOpenSSL.tex b/doc/pyOpenSSL.tex
index cf69e0f..65cff3e 100644
--- a/doc/pyOpenSSL.tex
+++ b/doc/pyOpenSSL.tex
@@ -725,10 +725,20 @@
 The operation did not complete; the same I/O method should be called again
 later, with the same arguments. Any I/O method can lead to this since new
 handshakes can occur at any time.
+
+The wanted read is for "dirty" data sent over the network, not the 
+"clean" data inside the tunnel.  For a socket based SSL connection, 
+"read" means data coming at us over the network.  Until
+that read succeeds, the attempted 
+\method{OpenSSL.SSL.Connection.recv}, 
+\method{OpenSSL.SSL.Connection.send}, or
+\method{OpenSSL.SSL.Connection.do_handshake} is prevented or incomplete.
+You probably want to \method{select()} on the socket before trying again.
 \end{excdesc}
 
 \begin{excdesc}{WantWriteError}
-See \exception{WantReadError}.
+See \exception{WantReadError}.  The socket may be too full to
+write more data.
 \end{excdesc}
 
 \begin{excdesc}{WantX509LookupError}