--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,9 @@
+2011-04-03  Rik  <octave@nomad.inbox5.com>
+
+	* interpreter/grammar.txi, interpreter/octave.texi: Add new section
+	on parsing to documentation.  Add functions add_input_event_hook,
+	remove_input_event_hook, missing_function_hook to documentation.
+
 2011-04-03  Rik  <octave@nomad.inbox5.com>
 
 	* interpreter/linalg.txi: Add blkmm function to documentation.

--- a/doc/interpreter/grammar.txi
+++ b/doc/interpreter/grammar.txi
@@ -16,16 +16,17 @@
 @c along with Octave; see the file COPYING.  If not, see
 @c <http://www.gnu.org/licenses/>.
 
-@node Grammar
-@appendix Grammar
+@node Grammar and Parser
+@appendix Grammar and Parser
 @cindex grammar rules
 @cindex language definition
 
-This appendix should eventually contain a semi-formal description of
+This appendix will eventually contain a semi-formal description of
 Octave's language.
 
 @menu
 * Keywords::                    
+* Parser::                    
 @end menu
 
 @node Keywords
@@ -52,4 +53,33 @@
 @item @code{unwind_protect_cleanup}@tab @code{while}
 @end multitable
 
+The function @code{iskeyword} can be used to quickly check whether an
+identifier is reserved by Octave.
+
 @DOCSTRING(iskeyword)
+
+@node Parser
+@section Parser
+@cindex parser
+
+The parser has a number of variables that affect its internal operation.
+These variables are generally documented in the manual alongside the code that
+they affect.  For example, @code{allow_noninteger_range_as_index} is discussed
+in the section on index expressions.
+
+In addition, there are three non-specific parser customization functions.
+@code{add_input_event_hook} can be used to schedule a user function for
+periodic evaluation.  @code{remove_input_event_hook} will stop a user function
+from being evaluated periodically.
+
+@DOCSTRING(add_input_event_hook)
+
+@DOCSTRING(remove_input_event_hook)
+
+Finally, when the parser cannot identify an input token it calls a particular
+function to handle this.  By default, this is the function "unimplemented"
+which makes suggestions about possible Octave substitutes for @sc{matlab}
+functions.
+
+@DOCSTRING(missing_function_hook)
+

--- a/doc/interpreter/octave.texi
+++ b/doc/interpreter/octave.texi
@@ -209,7 +209,7 @@
 * Trouble::                     If you have trouble installing Octave.
 * Installation::                How to configure, compile and install Octave.
 * Emacs Octave Support::                       
-@c * Grammar::                     
+* Grammar and Parser::                     
 * Copying::                     The GNU General Public License.
 * Concept Index::               An item for each concept.
 * Function Index::              An item for each documented function.
@@ -854,6 +854,12 @@
 * Using Octave Mode::           
 * Running Octave from Within Emacs::  
 * Using the Emacs Info Reader for Octave::  
+
+Grammar and Parser
+
+* Keywords::                    
+* Parser::                    
+
 @end detailmenu
 @end menu
 
@@ -912,7 +918,7 @@
 @include bugs.texi
 @include install.texi
 @include emacs.texi
-@c @include grammar.texi
+@include grammar.texi
 @include gpl.texi
 
 @c ------------------------------------------------------------------------

--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2011-04-03  Rik  <octave@nomad.inbox5.com>
+
+	* input.cc (add_input_event_hook, remove_input_event_hook): Improve
+	docstring.
+	* utils.cc (isvarname): Add seealso link to iskeyword().
+	* variables.cc (missing_function_hook): Improve docstring.
+
 2011-04-03  Rik  <octave@nomad.inbox5.com>
 
 	* DLD-FUNCTIONS/dot.cc (blkmm): Improve docstring.

--- a/src/input.cc
+++ b/src/input.cc
@@ -1277,7 +1277,8 @@
 
 DEFUN (add_input_event_hook, args, ,
   "-*- texinfo -*-\n\
-@deftypefn {Built-in Function} {} add_input_event_hook (@var{fcn}, @var{data})\n\
+@deftypefn  {Built-in Function} {} add_input_event_hook (@var{fcn})\n\
+@deftypefnx {Built-in Function} {} add_input_event_hook (@var{fcn}, @var{data})\n\
 Add the named function @var{fcn} to the list of functions to call\n\
 periodically when Octave is waiting for input.  The function should\n\
 have the form\n\
@@ -1323,7 +1324,7 @@
 DEFUN (remove_input_event_hook, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} remove_input_event_hook (@var{fcn})\n\
-Remove the named function @var{fcn} to the list of functions to call\n\
+Remove the named function @var{fcn} from the list of functions to call\n\
 periodically when Octave is waiting for input.\n\
 @seealso{add_input_event_hook}\n\
 @end deftypefn")

--- a/src/utils.cc
+++ b/src/utils.cc
@@ -94,7 +94,7 @@
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} isvarname (@var{name})\n\
 Return true if @var{name} is a valid variable name.\n\
-@seealso{exist, who}\n\
+@seealso{iskeyword, exist, who}\n\
 @end deftypefn")
 {
   octave_value retval;

--- a/src/variables.cc
+++ b/src/variables.cc
@@ -2521,8 +2521,8 @@
     "-*- texinfo -*-\n\
 @deftypefn  {Built-in Function} {@var{val} =} missing_function_hook ()\n\
 @deftypefnx {Built-in Function} {@var{old_val} =} missing_function_hook (@var{new_val})\n\
-Query or set the internal variable that allows setting a custom hook function\n\
-called when an uknown identifier is requested.\n\
+Query or set the internal variable that specifies the function to call when\n\
+an unknown identifier is requested.\n\
 @end deftypefn")
 {
   return SET_INTERNAL_VARIABLE (missing_function_hook);