minor markup nits

Doc/ref/ref3.tex

@@ -1983,9 +1983,9 @@ Called to implement the built-in functions
 \end{methoddesc}
 
 \begin{methoddesc}[numeric object]{__index__}{self}
-Called to implement operator.index().  Also called whenever Python
-needs an integer object (such as in slicing).  Must return an integer
-(int or long).
+Called to implement \function{operator.index()}.  Also called whenever
+Python needs an integer object (such as in slicing).  Must return an
+integer (int or long).
 \versionadded{2.5}
 \end{methoddesc}
 

Doc/ref/ref5.tex

@@ -391,7 +391,8 @@ type but a string of exactly one character.
 
 A slicing selects a range of items in a sequence object (e.g., a
 string, tuple or list).  Slicings may be used as expressions or as
-targets in assignment or del statements.  The syntax for a slicing:
+targets in assignment or \keyword{del} statements.  The syntax for a
+slicing:
 \obindex{sequence}
 \obindex{string}
 \obindex{tuple}