\begin{mathematica}
<< /usr2/apps/mathematica/SystemFiles/Kernel/TextResources/English/Usage.m
\end{mathematica}

\begin{mathematica}
hnl = {#, ToExpression[# <> "::usage"]}& /@ Names["System`*"];
\end{mathematica}

\begin{mathematica}
(
nousage = {};
obsolete = {};
option = {};
symbol = {};
attribute = {};
variable = {};
gprimitive = {};
gdirective = {};
constant = {};
function = {};
other = {};
Which[
  !StringQ[#[[2]]], AppendTo[nousage, #[[1]]],
  StringMatchQ[#[[2]], "*is an obsolete*"], AppendTo[obsolete, #[[1]]],
  MemberQ[Attributes[#], Flat|OneIdentity|Listable|Orderless]& @ #[[1]], AppendTo[function, #[[1]]],
  StringMatchQ[#[[2]], "*is an option*"] || StringMatchQ[#[[2]], "*is a setting*"] || #[[1]] == "Automatic", AppendTo[option, #[[1]]],
  StringMatchQ[#[[2]], "*is a symbol*"] || StringMatchQ[#[[2]], "*is the symbol*"] || StringMatchQ[#[[2]], "*is the head*"] || #[[1]] == "List", AppendTo[symbol, #[[1]]],
  StringMatchQ[#[[2]], "*is an attribute*"], AppendTo[attribute, #[[1]]],
  StringTake[#[[1]], 1] == "$", AppendTo[variable, #[[1]]],
  StringMatchQ[#[[2]], "*is a@ primitive*"], AppendTo[gprimitive, #[[1]]],
  StringMatchQ[#[[2]], "*is a@ directive*"], AppendTo[gdirective, #[[1]]],
  MemberQ[Attributes[#], Constant]& @ #[[1]], AppendTo[constant, #[[1]]],
  True, AppendTo[other, #[[1]]]
]& /@ hnl;
)
\end{mathematica}
\begin{mathematica}
{nousage, obsolete, function, option, symbol, attribute, variable, gprimitive,
  gdirective, constant, other}[[11]];
\end{mathematica}
\begin{mathematica}
strlist[x_List] := Fold[ (#1 <> " \"" <> #2 <> "\"")&, "", x]
\end{mathematica}

\begin{mathematica}
(s = OpenWrite["/usr/contrib/share/xemacs/site-lisp/mma-font-lock.el"];
WriteString[s, ";;; This file was generated automatically by fontlock.m\n;;;
Tomasz J. Cholewo <t.cholewo@ieee.org>\n(eval-when-compile
(load-library \"make-regexp\"))\n(defvar math-font-lock-keywords (list\n"];
MapThread[
  If[ Length[Symbol[#1]] > 0, 
    WriteString[s, ";;; " <> #1 <> 
      "s\n  (cons (eval-when-compile (concat \"\\\\b\" (make-regexp '(" <> 
      strlist[Symbol[#1]] <> ") t) \"\\\\b\")) font-lock-" <> #2 <> "-face)\n"]]&,
  {{"function", "option", "symbol", "attribute", "variable",
   "gprimitive", "gdirective", "constant", "other"},
  {"keyword", "type", "type", "type", "function-name",
  "comment", "comment", "function-name", "preprocessor"}}];
WriteString[s, "  )\n  \"Mathematica 3.0 font-lock regular expressions\")\n(provide 'mma-font-lock)\n"];
Close[s];)
\end{mathematica}


\begin{mathematica}
Select[#[[1]]& /@ hnl, MemberQ[ Attributes[#], Locked]&]
.
Out[19]= {}
\end{mathematica}