Another try at clarifying what goes into and comes out of Unicode objects.
diff --git a/Doc/ref/ref2.tex b/Doc/ref/ref2.tex
index 4947650..b2ffa6f 100644
--- a/Doc/ref/ref2.tex
+++ b/Doc/ref/ref2.tex
@@ -410,29 +410,48 @@
\index{Standard C}
\index{C}
-\begin{tableii}{l|l}{code}{Escape Sequence}{Meaning}
-\lineii{\e\var{newline}} {Ignored}
-\lineii{\e\e} {Backslash (\code{\e})}
-\lineii{\e'} {Single quote (\code{'})}
-\lineii{\e"} {Double quote (\code{"})}
-\lineii{\e a} {\ASCII{} Bell (BEL)}
-\lineii{\e b} {\ASCII{} Backspace (BS)}
-\lineii{\e f} {\ASCII{} Formfeed (FF)}
-\lineii{\e n} {\ASCII{} Linefeed (LF)}
-\lineii{\e N\{\var{name}\}}
- {Character named \var{name} in the Unicode database (Unicode only)}
-\lineii{\e r} {\ASCII{} Carriage Return (CR)}
-\lineii{\e t} {\ASCII{} Horizontal Tab (TAB)}
-\lineii{\e u\var{xxxx}} {Character with 16-bit hex value \var{xxxx} (Unicode only)}
-\lineii{\e U\var{xxxxxxxx}}{Character with 32-bit hex value \var{xxxxxxxx} (Unicode only)}
-\lineii{\e v} {\ASCII{} Vertical Tab (VT)}
-\lineii{\e\var{ooo}} {\ASCII{} character with octal value \var{ooo}}
-\lineii{\e x\var{hh}} {\ASCII{} character with hex value \var{hh}}
-\end{tableii}
+\begin{tableiii}{l|l|c}{code}{Escape Sequence}{Meaning}{Notes}
+\lineiii{\e\var{newline}} {Ignored}{}
+\lineiii{\e\e} {Backslash (\code{\e})}{}
+\lineiii{\e'} {Single quote (\code{'})}{}
+\lineiii{\e"} {Double quote (\code{"})}{}
+\lineiii{\e a} {\ASCII{} Bell (BEL)}{}
+\lineiii{\e b} {\ASCII{} Backspace (BS)}{}
+\lineiii{\e f} {\ASCII{} Formfeed (FF)}{}
+\lineiii{\e n} {\ASCII{} Linefeed (LF)}{}
+\lineiii{\e N\{\var{name}\}}
+ {Character named \var{name} in the Unicode database (Unicode only)}{}
+\lineiii{\e r} {\ASCII{} Carriage Return (CR)}{}
+\lineiii{\e t} {\ASCII{} Horizontal Tab (TAB)}{}
+\lineiii{\e u\var{xxxx}}
+ {Character with 16-bit hex value \var{xxxx} (Unicode only)}{(1)}
+\lineiii{\e U\var{xxxxxxxx}}
+ {Character with 32-bit hex value \var{xxxxxxxx} (Unicode only)}{(2)}
+\lineiii{\e v} {\ASCII{} Vertical Tab (VT)}{}
+\lineiii{\e\var{ooo}} {\ASCII{} character with octal value \var{ooo}}{(3)}
+\lineiii{\e x\var{hh}} {\ASCII{} character with hex value \var{hh}}{(4)}
+\end{tableiii}
\index{ASCII@\ASCII}
-As in Standard C, up to three octal digits are accepted. However,
-exactly two hex digits are taken in hex escapes.
+\noindent
+Notes:
+
+\begin{itemize}
+\item[(1)]
+ Individual code units which form parts of a surrogate pair can be
+ encoded using this escape sequence.
+\item[(2)]
+ Any Unicode character can be encoded this way, but characters
+ outside the Basic Multilingual Plane (BMP) will be encoded using a
+ surrogate pair if Python is compiled to use 16-bit code units (the
+ default). Individual code units which form parts of a surrogate
+ pair can be encoded using this escape sequence.
+\item[(3)]
+ As in Standard C, up to three octal digits are accepted.
+\item[(4)]
+ Unlike in Standard C, at most two hex digits are accepted.
+\end{itemize}
+
Unlike Standard \index{unrecognized escape sequence}C,
all unrecognized escape sequences are left in the string unchanged,
@@ -460,12 +479,12 @@
When an \character{r} or \character{R} prefix is used in conjunction
with a \character{u} or \character{U} prefix, then the \code{\e uXXXX}
escape sequence is processed while \emph{all other backslashes are
-left in the string}. For example, the string literal \code{ur"\e
-u0062\e n"} consists of three Unicode characters: `LATIN SMALL LETTER
-B', `REVERSE SOLIDUS', and `LATIN SMALL LETTER N'. Backslashes can be
-escaped with a preceding backslash; however, both remain in the
-string. As a result, \code{\e uXXXX} escape sequences are only
-recognized when there are an odd number of backslashes.
+left in the string}. For example, the string literal
+\code{ur"\e{}u0062\e n"} consists of three Unicode characters: `LATIN
+SMALL LETTER B', `REVERSE SOLIDUS', and `LATIN SMALL LETTER N'.
+Backslashes can be escaped with a preceding backslash; however, both
+remain in the string. As a result, \code{\e uXXXX} escape sequences
+are only recognized when there are an odd number of backslashes.
\subsection{String literal concatenation\label{string-catenation}}