diff --git a/MATL_spec.pdf b/MATL_spec.pdf
index aafaf68..428bbef 100644
Binary files a/MATL_spec.pdf and b/MATL_spec.pdf differ
diff --git a/funDef.mat b/funDef.mat
index 3164371..b9805cc 100644
Binary files a/funDef.mat and b/funDef.mat differ
diff --git a/funDef.txt b/funDef.txt
index d3187b9..196d1fa 100644
--- a/funDef.txt
+++ b/funDef.txt
@@ -24,10 +24,10 @@ Z!	1	1	1	1	1	1	true	true	out{1} = full(in{1});	convert sparse matrix to full mat
 X"	2	inf	3	1	1	1	true	true	out{1} = repmat(in{:});	replicate and tile array	\matlab+repmat+
 Y"	2	inf	2	1	1	1	true	true	out{1} = repelem(in{:});	replicate elements of array	\matlab+repelem+ (run-length decoding)
 Z"	1	1	1	1	1	1	true	true	out{1} = blanks(in{1});	string of blanks	\matlab+blanks+
-#	1	1	1	0	0	0	false	false	S_OUT = STACK{end}; STACK(end) = [];	output specification	specify outputs for next function
+#
 % The numbers of inputs and outputs for # are not used by the code, but are used for generating the help file
 X#	
-Y#	1	2	1	0	0	0	true	true	rng(in{:});	control the random number generator	\matlab+rng+
+Y#
 Z#	1	3	1	0	0	0	true	true	data = in{1}; if ~iscell(data), data = {data}; end	write to file	Appends first input to file \comp{inout}, creating it if necessary. If the input is an array it is converted to char and written. If the input is a cell array input, the contents of each cell are converted to char and written, with a newline (character 10) in between. With $2$ inputs: second input specifies filename; if empty defaults to \comp{inout}. With $3$ inputs: third input specifies whether any previous contents of file should be kept.
 									sep = char(10);
 									if numel(in)>=2 && ~isempty(in{2}), file = in{2}; else file = 'inout'; end
@@ -38,7 +38,7 @@ Z#	1	3	1	0	0	0	true	true	data = in{1}; if ~iscell(data), data = {data}; end	writ
 									if n<numel(data), fwrite(fid, sep); end
 									end
 									fclose(fid);
-$	1	1	1	0	0	0	false	false	S_IN = STACK{end}; STACK(end) = [];	input specification	specify inputs for next function
+$
 % The numbers of inputs and outputs for # are not used by the code, but are used for generating the help file
 X$	1	inf	2	0	inf	1	true	true	[out{:}] = feval(in{:});	execute Matlab function	execute Matlab function specified by first input, using the rest of the inputs as arguments.
 Y$	1	2	1	1	1	1	true	true	out{1} = char(vpa(in{:}));	variable precision arithmetic	\matlab+char(vpa(...))+
@@ -309,7 +309,8 @@ YB	1	2	1	1	1	1	true	true	out{1} = dec2bin(in{:});	convert decimal number to bina
 ZB	1	1	1	1	1	1	true	true	out{1} = bin2dec(in{1});	convert binary string to decimal number	\matlab|bin2dec|
 C					
 XC	1	7	2	1	3	1	true	true	[out{:}] = histcounts(in{:});	histogram bin counts	\matlab+histcounts+
-YC	2	4	2	1	1	1	true	true	out{1} = im2col(in{:});	rearrange array blocks into columns	\matlab+im2col+
+YC	2	4	2	1	1	1	true	true	if numel(in{2})==1, if size(in{1},1)==1, in{2} = [1 in{2}]; else in{2} = [in{2} 1]; end; end	rearrange array blocks into columns	\matlab+im2col+. If the second input is a scalar n, it is transformed into [1 n] if the first input is a row vector, or to [n 1] otherwise
+									out{1} = im2col(in{:});
 ZC
 D	0	inf	1	0	0	0	true	true	if numel(in)==1, data = in; fmt = {'%.16g '}; else data = in(1:end-1); fmt = in(end); end	convert to string and display	If $1$ input: \matlab+disp(num2str(..., '%.16g '))+. If several inputs: \matlab+disp(num2str(eachInput,lastInput))+, where \matlab+eachInput+ loops over all inputs but the last. In either case, (nested) cell arrays are (recursively) unboxed in linear order. \sa \matl+XD+, \matl+YD+, \matl+ZD+
 									kk = cellfun(@iscell, data); 
diff --git a/genHelp.m b/genHelp.m
index 464fd27..ad92fe2 100644
--- a/genHelp.m
+++ b/genHelp.m
@@ -13,6 +13,14 @@
 
 % Statements that are not functions. Changes done here to the comment field should be
 % done in `matl_disp.m` too.
+F(end+1).source = '$';
+F(end).comment = 'input specification';
+F(end).description = 'specify inputs for next function';
+
+F(end+1).source = '#';
+F(end).comment = 'otput specification';
+F(end).description = 'specify outputs for next function';
+
 F(end+1).source = '"';
 F(end).comment = 'for';
 F(end).description = '\matlab+for+ (control flow: loop). \sa \matl+]+, \matl+@+, \matl+X}+, \matl+Y}+';
diff --git a/help.mat b/help.mat
index 28599a7..5bd6bbe 100644
Binary files a/help.mat and b/help.mat differ
diff --git a/matl.m b/matl.m
index 5e17671..6122494 100644
--- a/matl.m
+++ b/matl.m
@@ -200,11 +200,12 @@ function matl(varargin)
 end
 
 % Call help, if required, and quit
+useTags = isMatlab && (verNum(1)>7 || (verNum(1)==7 && verNum(2)>=13));
 if any(options=='h')
     if nargin>1
-        matl_help(H, s, verbose, isMatlab, verNum)
+        matl_help(H, s, verbose, useTags)
     else
-        matl_help(H, '', verbose, isMatlab, verNum)
+        matl_help(H, '', verbose, useTags)
     end
     return
 end
@@ -214,7 +215,7 @@ function matl(varargin)
     if verbose
         disp('Parsing program')
     end
-    S = matl_parse(s);
+    S = matl_parse(s, useTags);
     if verbose
         if numel(S)~=1
             fprintf('  %i statements parsed\n', numel(S))
@@ -239,7 +240,7 @@ function matl(varargin)
     if verbose
         disp('Compiling program')
     end
-    S = matl_compile(S, F, L, pOutFile, cOutFile, verbose, isMatlab);
+    S = matl_compile(S, F, L, pOutFile, cOutFile, verbose, isMatlab, useTags);
     %if verbose
     %    disp('  Done.')
     %end
@@ -253,7 +254,7 @@ function matl(varargin)
         %disp('--') %disp(repmat('-',size(str)))
         pause
     end
-    matl_run(S, pOutFile, cOutFileNoExt, [], isMatlab) % ...NoExt because a file name without extension is
+    matl_run(S, pOutFile, cOutFileNoExt, [], isMatlab, useTags) % ...NoExt because a file name without extension is
     % needed in old Matlab versions   
 end
 
@@ -263,7 +264,7 @@ function matl(varargin)
         disp('Press any key to run MATL program in debug mode')
         pause
     end
-    matl_run(S, pOutFile, cOutFileNoExt, [S.compileLine], isMatlab) % ...NoExt because a file name without
+    matl_run(S, pOutFile, cOutFileNoExt, [S.compileLine], isMatlab, useTags) % ...NoExt because a file name without
     % extension is needed in old Matlab versions
 end
 
diff --git a/matl_compile.m b/matl_compile.m
index 5c1386c..893f32b 100644
--- a/matl_compile.m
+++ b/matl_compile.m
@@ -1,4 +1,4 @@
-function S = matl_compile(S, F, L, pOutFile, cOutFile, verbose, isMatlab)
+function S = matl_compile(S, F, L, pOutFile, cOutFile, verbose, isMatlab, useTags)
 %
 % MATL compiler. Compiles into MATLAB code.
 % Input: struct array with parsed statements.
@@ -21,21 +21,41 @@
 %
 % Luis Mendo
 
-global indStepComp
-global C
+global indStepComp C implicitInputBlock
 
 indStepComp = 4;
 
+if verbose
+    disp('  Generating compiled code')
+end
+
 Fsource = {F.source}; % this field of `F` will be used often
 
 % Possible improvement: preallocate for greater speed, and modify
 % appendLines so that C doesn't dynamically grow
 C = {}; % Cell array of strings. Each cell contains a line of compiled (MATLAB) code
 
-if verbose
-    disp('  Generating compiled code')
+if useTags
+    strongBegin = '<strong>';
+    strongEnd = '</strong>';
+else
+    strongBegin = '';
+    strongEnd = '';
 end
 
+% Define blocks of code that will be reused
+implicitInputBlock = {...
+    'if ~isempty(nin) && (numel(STACK)+nin(1)<1)' ...
+    'implInput = {};' ...
+    'for k = 1:1-numel(STACK)-nin(1)' ...
+    'implInput{k} = input(implicitInputPrompt,''s'');' ...
+    'assert(isempty(regexp(implInput{k}, ''^[^'''']*(''''[^'''']*''''[^'''']*)*[a-zA-Z]{2}'', ''once'')), ''MATL:runtime'', ''MATL run-time error: input not allowed'')' ...
+    'if isempty(implInput{k}), implInput{end} = []; else implInput{k} = eval(implInput{k}); end' ...
+    'end' ...
+    'STACK = [implInput STACK];' ...
+    'clear implInput k' ...
+    'end'};
+
 % Include function header
 [~, name] = fileparts(cOutFile);
 appendLines(['function ' name], 0)
@@ -61,6 +81,7 @@
 appendLines('P = pi; Y = inf; N = NaN; M = -1; G = -1j;', 0)
 % Constants to be used by function code
 appendLines('defaultInputPrompt = ''> '';', 0);
+appendLines('implicitInputPrompt = ''> '';', 0);
 % Predefine literals for functions
 if ~isempty(S)
     plf = cellstr(char(bsxfun(@plus, 'X0', [floor(0:.1:2.9).' repmat((0:9).',3,1)]))).'; % {'X0'...'Z9'}
@@ -101,8 +122,18 @@
         case 'literal.logicalRowArray'
             lit = strrep(strrep(S(n).source,'T','true,'),'F','false,');
             lit = ['[' lit(1:end-1) ']'];
-            appendLines(['STACK{end+1} = ' lit ';'], S(n).nesting)            
+            appendLines(['STACK{end+1} = ' lit ';'], S(n).nesting)
+        case 'metaFunction.inSpec'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
+            appendLines('S_IN = STACK{end}; STACK(end) = [];', S(n).nesting)
+        case 'metaFunction.outSpec'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
+            appendLines('S_OUT = STACK{end}; STACK(end) = [];', S(n).nesting)
         case 'controlFlow.for'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
             newLines{1} = sprintf('in = STACK{end}; STACK(end) = []; indFor%i = 0;', S(n).nesting);
             newLines{2} = sprintf('for varFor%i = in', S(n).nesting);
             appendLines(newLines, S(n).nesting)
@@ -117,6 +148,8 @@
             newLines = sprintf('indDoWhile%i = indDoWhile%i+1;', S(n).nesting, S(n).nesting);
             appendLines(newLines, S(n).nesting+1)
         case 'controlFlow.while' % 'X`'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
             newLines = { sprintf('indWhile%i = 0;', S(n).nesting) ...
                 sprintf('condWhile%i = STACK{end};', S(n).nesting) ...
                 'STACK(end) = [];' ... 
@@ -125,6 +158,8 @@
             newLines = sprintf('indWhile%i = indWhile%i+1;', S(n).nesting, S(n).nesting);
             appendLines(newLines, S(n).nesting+1)
         case 'controlFlow.if' % '?'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
             newLines = { 'in = STACK{end}; STACK(end) = [];' ...
                 'if in' };
             appendLines(newLines, S(n).nesting);
@@ -132,12 +167,16 @@
             appendLines('else', S(n).nesting)
         case 'controlFlow.end' % ']'
             if strcmp(S(S(n).from).type, 'controlFlow.doWhile')
+                appendLines('nin = 0;', S(n).nesting);
+                appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
                 newLines = { sprintf('condDoWhile%i = STACK{end};', S(n).nesting) ...
                     'STACK(end) = [];' ...
                     'end' ...
                     sprintf('clear indDoWhile%i', S(n).nesting)};
                 appendLines(newLines, S(n).nesting)
             elseif strcmp(S(S(n).from).type, 'controlFlow.while')
+                appendLines('nin = 0;', S(n).nesting);
+                appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
                 newLines = { sprintf('condWhile%i = STACK{end};', S(n).nesting) ...
                     'STACK(end) = [];' ...
                     'end' ...
@@ -151,11 +190,15 @@
                 newLines = 'end';
                 appendLines(newLines, S(n).nesting);
             else
-                error('MATL:compiler:internal', 'MATL internal error while compiling statement <strong>%s</strong>', S(n).source)
+                error('MATL:compiler:internal', 'MATL internal error while compiling statement %s%s%s', strongBegin, S(n).source, strongEnd)
             end
         case 'controlFlow.conditionalBreak'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
             appendLines('in = STACK{end}; STACK(end) = []; if in, break, end', S(n).nesting)
         case 'controlFlow.conditionalContinue'
+            appendLines('nin = 0;', S(n).nesting);
+            appendLines(implicitInputBlock, S(n).nesting); % code block for implicit input
             appendLines('in = STACK{end}; STACK(end) = []; if in, continue, end', S(n).nesting)
         case 'controlFlow.forValue'
             k = S(S(n).from).nesting;
@@ -169,13 +212,17 @@
         case 'function'
             k = find(strcmp(S(n).source, Fsource), 1); % Fsource is guaranteed to contain unique entries.
             if isempty(k)
-                error('MATL:compiler', 'MATL error while compiling: function <strong>%s</strong> in <a href="matlab: opentoline(''%s'', %i)">statement number %i</a> not defined in MATL', S(n).source, pOutFile, n, n)
+                if useTags
+                    error('MATL:compiler', 'MATL error while compiling: function %s%s%s in <a href="matlab: opentoline(''%s'', %i)">statement number %i</a> not defined in MATL', strongBegin, S(n).source, strongEnd, pOutFile, n, n)
+                else
+                    error('MATL:compiler', 'MATL error while compiling: function %s%s%s in statement number %i not defined in MATL', strongBegin, S(n).source, strongEnd, n)
+                end
             end
             appendLines(funWrap(F(k).minIn, F(k).maxIn, F(k).defIn, F(k).minOut, F(k).maxOut, F(k).defOut, ...
                 F(k).consumeInputs, F(k).wrap, F(k).body), S(n).nesting)
             C = [C strcat(blanks(indStepComp*S(n).nesting), newLines)];
         otherwise
-            error('MATL:compiler:internal', 'MATL internal error while compiling statement <strong>%s</strong>: unrecognized statement type', S(n).source)
+            error('MATL:compiler:internal', 'MATL internal error while compiling statement %s%s%s: unrecognized statement type', strongBegin, S(n).source, strongEnd)
     end
 end
 
@@ -192,22 +239,22 @@
     appendLines('% Define subfunctions', 0)
     appendLines('', 0)
     appendLines({...
-        'function y = num2str(varargin)';
-        'x = varargin{1}; x = reshape(x, size(x,1),[]);';
-        'if nargin==1 || ischar(varargin{1}) || isnumeric(varargin{2})'; % normal `num2str` function
-        'y = builtin(''num2str'', varargin{:});';
-        'else'; % interception
-        'fmt = varargin{2}; y = sprintf([fmt ''\n''], x.''); y = regexp(y, ''\n'', ''split''); y = y(1:end-1).'';';
-        'y = cellfun(@fliplr, y, ''uniformoutput'', false); y = char(y); y = fliplr(y);';
-        'y = reshape(y.'',[],size(x,1)).''; y = strtrim(y);';
-        'end';
+        'function y = num2str(varargin)' ...
+        'x = varargin{1}; x = reshape(x, size(x,1),[]);'  ...
+        'if nargin==1 || ischar(varargin{1}) || isnumeric(varargin{2}) || any(imag(x(:)))' ... % normal `num2str` function
+        'y = builtin(''num2str'', varargin{:});' ...
+        'else' ... % interception
+        'fmt = varargin{2}; y = sprintf([fmt ''\n''], x.''); y = regexp(y, ''\n'', ''split''); y = y(1:end-1).'';'  ...
+        'y = cellfun(@fliplr, y, ''uniformoutput'', false); y = char(y); y = fliplr(y);' ...
+        'y = reshape(y.'',[],size(x,1)).''; y = strtrim(y);' ...
+        'end' ...
         'end'}, 0)
     % im2col
     appendLines('', 0)
     appendLines({...
-        'function y = im2col(varargin)';
-        'argin1 = varargin{1}; argin1 = reshape(argin1, size(argin1,1), []);';
-        'y = builtin(''im2col'', argin1, varargin{2:end});';
+        'function y = im2col(varargin)' ...
+        'argin1 = varargin{1}; argin1 = reshape(argin1, size(argin1,1), []);' ...
+        'y = builtin(''im2col'', argin1, varargin{2:end});' ...
         'end'}, 0)    
 end
 
@@ -239,19 +286,22 @@
 % Code generated at the beginning of functions: check S_IN and S_OUT,
 % get inputs, prepare outputs, consume inputs if applicable.
 % `consume` indicates if inputs should be removed from the stack
+global implicitInputBlock
 newLines = { ...
     sprintf('if isempty(S_IN), S_IN = %s; end', defIn) ...
     sprintf('if isnumeric(S_IN) && numel(S_IN) == 1, if S_IN < %s || S_IN > %s, error(''MATL:runner'', ''MATL run-time error: incorrect input specification''), end', minIn, maxIn) ...
     sprintf('elseif islogical(S_IN), if nnz(S_IN) < %s || nnz(S_IN) > %s, error(''MATL:runner'', ''MATL run-time error: incorrect input specification''), end', minIn, maxIn) ...
     'else error(''MATL:runner'', ''MATL run-time error: input specification not recognized''), end' ...
-    'if isnumeric(S_IN), nin = -S_IN+1:0; else nin = find(S_IN)-numel(S_IN); end' ...
+    'if isnumeric(S_IN), nin = -S_IN+1:0; else nin = find(S_IN)-numel(S_IN); end'};
+newLines = [newLines implicitInputBlock]; % code block for implicit input
+newLines = [newLines, {...
     'in = STACK(end+nin);' ...
     sprintf('if isempty(S_OUT), S_OUT = %s; end', defOut) ...
     sprintf('if isnumeric(S_OUT) && numel(S_OUT) == 1, if S_OUT < %s || S_OUT > %s, error(''MATL:runner'', ''MATL run-time error: incorrect output specification''), end', minOut, maxOut) ...
     sprintf('elseif islogical(S_OUT), if numel(S_OUT) < %s || numel(S_OUT) > %s, error(''MATL:runner'', ''MATL run-time error: incorrect output specification''), end', minOut, maxOut) ...
     'else error(''MATL:runner'', ''MATL run-time error: output specification not recognized''), end' ...
     'if isnumeric(S_OUT), nout = S_OUT; else nout = numel(S_OUT); end' ...
-    'out = cell(1,nout);' };
+    'out = cell(1,nout);' }];
 % For logical S_IN we use nnz (the inputs are picked from the stack), but
 % for logical S_OUT we use numel (the function is called with that many outputs)
 if consume
diff --git a/matl_disp.m b/matl_disp.m
index 726c501..8f5eade 100644
--- a/matl_disp.m
+++ b/matl_disp.m
@@ -51,6 +51,8 @@ function matl_disp(S, F, indentBase, indentStep, indentCommentSymbol, indentComm
         texts(ismember(Stype, {'literal.logicalRowArray'})) = {'logical row array literal'};
         texts(ismember(Stype, {'literal.cellArray'})) = {'cell array literal'};
         texts(ismember(Stype, {'literal.string'})) = {'string literal'};
+        texts(strcmp(Stype, 'metaFunction.inSpec')) = {'input specification'};
+        texts(strcmp(Stype, 'metaFunction.outSpec')) = {'output specification'};
         texts(strcmp(Stype, 'controlFlow.for')) = {'for'};
         texts(strcmp(Stype, 'controlFlow.doWhile')) = {'do...while'};
         texts(strcmp(Stype, 'controlFlow.while')) = {'while'};
diff --git a/matl_help.m b/matl_help.m
index 6c233bb..6cc7675 100644
--- a/matl_help.m
+++ b/matl_help.m
@@ -1,4 +1,4 @@
-function matl_help(H, strHelp, verbose, isMatlab, verNum)
+function matl_help(H, strHelp, verbose, useTags)
 %
 % MATL help.
 %
@@ -9,35 +9,44 @@ function matl_help(H, strHelp, verbose, isMatlab, verNum)
 if verbose
     disp('MATL help:')
 end
+
+if useTags
+    strongBegin = '<strong>';
+    strongEnd = '</strong>';
+else
+    strongBegin = '';
+    strongEnd = '';
+end
+
 if isempty(strHelp) || strcmp(strHelp,'help') % empty string: show help usage and return
     if verbose
-        disp('  General help')
-        disp(' ')
+        fprintf('  General help\n')
+        fprintf('\n')
     end
-    disp('<strong>matl</strong> usage:')
-    disp('First input: options:')
-    disp('  <strong>-p</strong>: parse')
-    disp('  <strong>-l</strong>: listing. Numeric options specify format')
-    disp('  <strong>-e</strong>: listing with comments. Numeric options specify format')
-    disp('  <strong>-c</strong>: compile')
-    disp('  <strong>-r</strong>: run (default)')
-    disp('  <strong>-d</strong>: debug')
-    disp('  <strong>-f</strong>: use file')
-    disp('  <strong>-v</strong>: verbose')
-    disp('  <strong>-h</strong>: help.')
-    disp('Second input: string:')
-    disp('  Contains source code, file name or search text')
-    disp('  Source code or file name can be omitted. In that case they are introduced later')
-    disp('  Search text can be a name of function or statement, or a word.')
+    fprintf('%smatl%s usage:\n', strongBegin, strongEnd)
+    fprintf('First input: options:\n')
+    fprintf('  %s-p%s: parse\n', strongBegin, strongEnd)
+    fprintf('  %s-l%s: listing. Numeric options specify format\n', strongBegin, strongEnd)
+    fprintf('  %s-e%s: listing with comments. Numeric options specify format\n', strongBegin, strongEnd)
+    fprintf('  %s-c%s: compile\n', strongBegin, strongEnd)
+    fprintf('  %s-r%s: run (default)\n', strongBegin, strongEnd)
+    fprintf('  %s-d%s: debug\n', strongBegin, strongEnd)
+    fprintf('  %s-f%s: use file\n', strongBegin, strongEnd)
+    fprintf('  %s-v%s: verbose\n', strongBegin, strongEnd)
+    fprintf('  %s-h%s: help.\n', strongBegin, strongEnd)
+    fprintf('Second input: string:\n')
+    fprintf('  Contains source code, file name or search text\n')
+    fprintf('  Source code or file name can be omitted. In that case they are introduced later\n')
+    fprintf('  Search text can be a name of function or statement, or a word.\n')
     return
 elseif numel(strHelp)==1 || (numel(strHelp)==2 && any(strHelp(1)=='XYZ'))  % search in source
     if verbose
-        disp('  Searching for statement with exact matching')
+        fprintf('  Searching for statement with exact matching\n')
     end
     ind = find(strcmp(H.sourcePlain, strHelp)); % exact search in source
 elseif ~isempty(strHelp) % search in comment or description
     if verbose
-        disp('  Searching for text, case-insensitive, partial matching')
+        fprintf('  Searching for text, case-insensitive, partial matching\n')
     end
     ind = find(~cellfun(@isempty, strfind(lower(H.comm), lower(strHelp))) |...
         ~cellfun(@isempty, strfind(lower(H.descrPlain), lower(strHelp)))); % partial, case-insentive search in comment and description
@@ -46,7 +55,7 @@ function matl_help(H, strHelp, verbose, isMatlab, verNum)
 if verbose && ~isempty(ind)
     disp(' ')
 end
-if isMatlab && (verNum(1)>7 || (verNum(1)==7 && verNum(2)>=13))
+if useTags
     descrFieldName = 'descr';
     sourceFieldName = 'source';
 else
diff --git a/matl_parse.m b/matl_parse.m
index bb9ac63..a69abf1 100644
--- a/matl_parse.m
+++ b/matl_parse.m
@@ -1,4 +1,4 @@
-function S = matl_parse(s)
+function S = matl_parse(s, useTags)
 %
 % MATL parser.
 %
@@ -16,6 +16,13 @@
 LF = char(10); % line feed in ASCII
 CR = char(13); % line feed in ASCII
 
+if useTags
+    strongBegin = '<strong>';
+    strongEnd = '</strong>';
+else
+    strongBegin = '';
+    strongEnd = '';
+end
 
 % Parse to separate into statements
 
@@ -72,9 +79,9 @@
         % Consume until ]. There may be other [ and ] in between (although it would be a waste of characters),
         % so consume until the number of [ minus ] reaches 0
         [ini, fin] = regexp(s(pos:end), '^\[([^\[\]]*\[[^\[\]]*\])*[^\[\]]*\]', 'once');
-        assert(ini==1, 'MATL:parser:internal', 'MATL internal error while parsing array literal')
+        assert(isequal(ini,1), 'MATL:parser', 'MATL error while parsing: array literal not well formed')
         if ~validateArray(s(pos:pos-1+fin))
-            error('MATL:parser:internal', 'Content not allowed in MATL array literal')
+            error('MATL:parser', 'Content not allowed in MATL array literal')
         end
         S(n).type = 'literal.array';
         S(n).source = s(pos:pos-1+fin);
@@ -86,7 +93,7 @@
         fin = find(~cumsum((s(pos:end)=='{')-(s(pos:end)=='}')),1);
         assert(~isempty(fin), 'MATL:parser', 'MATL error while parsing: cell array literal not closed')
         if ~validateArray(s(pos:pos-1+fin))
-            error('MATL:parser:internal', 'Content not allowed in MATL cell array literal')
+            error('MATL:parser', 'Content not allowed in MATL cell array literal')
         end
         S(n).type = 'literal.cellArray';
         S(n).source = s(pos:pos-1+fin);
@@ -100,7 +107,7 @@
         % `c` (`^''([^'']|'''')*?''(?!'')`) indicates string and 
         % `n` (`[+-]?(\d+\.?\d*|\d*\.?\d+)(e[+-]?\d+)?j?`) indicates number
         assert(~isempty(ini), 'MATL:parser', 'MATL error while parsing: string literal not closed')
-        assert(ini==1, 'MATL:parser:internal', 'MATL internal error while parsing string/colon array literal')
+        assert(isequal(ini,1), 'MATL:parser:internal', 'MATL internal error while parsing string/colon array literal')
         if any(s(pos:pos-1+fin)==':') % It's a (char) colon array literal
             S(n).type = 'literal.colonArray.char';
         else % It's a string
@@ -110,12 +117,24 @@
         S(n).nesting = parseNesting;
         pos = pos + fin;
         n = n + 1;
-    elseif any(s(pos)==['!#$&()*+-/:;<=>\^_|~' 'A':'W' 'a':'z'])
+    elseif any(s(pos)==['!&()*+-/:;<=>\^_|~' 'A':'W' 'a':'z'])
         S(n).type = 'function';
         S(n).source = s(pos);
         S(n).nesting = parseNesting;
         pos = pos + 1;
         n = n + 1;
+    elseif s(pos)=='$'
+        S(n).type = 'metaFunction.inSpec';
+        S(n).source = s(pos);
+        S(n).nesting = parseNesting;
+        pos = pos + 1;
+        n = n + 1;
+    elseif s(pos)=='#'
+        S(n).type = 'metaFunction.outSpec';
+        S(n).source = s(pos);
+        S(n).nesting = parseNesting;
+        pos = pos + 1;
+        n = n + 1;
     elseif s(pos)=='"' % for
         % We use fields "from", "end" and "else" to keep track of the
         % structure of loops and conditional branches.
@@ -226,7 +245,7 @@
         n = n + 1;
     elseif s(pos)=='%' % consume until LF or CR. Don't store in S
         [ini, fin] = regexp(s(pos:end),'^%[^\r\n]*[\r\n]?');
-        assert(ini==1, 'MATL:parser:internal', 'MATL internal error while parsing comment literal')
+        assert(isequal(ini,1), 'MATL:parser:internal', 'MATL internal error while parsing comment literal')
         pos = pos + fin;
         % There's no statement. Just move `pos` forward. Statement count n is not incremented
     elseif any(s(pos)==[', ' LF CR]) % do nothing, just consume (but that
@@ -259,7 +278,7 @@
                 error('MATL:parser', 'MATL error while parsing: ''conditional continue'' is not within any ''for'' loop')
             end
         elseif any(s(pos+1)==' ') % Not currently used after X. We can filter here or leave it to the compiler
-            error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> not recognized at position %d', s([pos pos+1]), pos)
+            error('MATL:parser', 'MATL error while parsing: %s%s%s not recognized at position %d', strongBegin, s([pos pos+1]), strongEnd, pos)
         else
             S(n).type = 'function';
             S(n).source = s([pos pos+1]);
@@ -269,7 +288,7 @@
         n = n + 1;
     elseif s(pos)=='Y' && pos<L
         if any(s(pos+1)==' ') % Not used after Y
-            error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> not recognized at position %d', s([pos pos+1]), pos)
+            error('MATL:parser', 'MATL error while parsing: %s%s%s not recognized at position %d', strongBegin, s([pos pos+1]), strongEnd, pos)
         else
             S(n).type = 'function';
             S(n).source = s([pos pos+1]);
@@ -279,7 +298,7 @@
         n = n + 1;
     elseif s(pos)=='Z' && pos<L
         if any(s(pos+1)==' ') % Not used after Z.
-            error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> not recognized at position %d', s([pos pos+1]), pos)
+            error('MATL:parser', 'MATL error while parsing: %s%s%s not recognized at position %d', strongBegin, s([pos pos+1]), strongEnd, pos)
         else
             S(n).type = 'function';
             S(n).source = s([pos pos+1]);
@@ -288,11 +307,11 @@
         pos = pos + 2;
         n = n + 1;
     elseif any(s(pos)=='''') % Not allowed.
-        error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> not recognized at position %d', s(pos), pos)
+        error('MATL:parser', 'MATL error while parsing: %s%s%s not recognized at position %d', strongBegin, s(pos), strongEnd, pos)
     elseif any(s(pos)=='XYZ') && pos==L
-        error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> not recognized at position %d', s(pos), pos)
+        error('MATL:parser', 'MATL error while parsing: %s%s%s not recognized at position %d', strongBegin, s(pos), strongEnd, pos)
     else
-        error('MATL:parser', 'MATL error while parsing: unknown character <strong>%s</strong> at position %d', s(pos), pos)
+        error('MATL:parser', 'MATL error while parsing: unknown character %s%s%s at position %d', strongBegin, s(pos), strongEnd, pos)
     end
 end
 
@@ -326,7 +345,7 @@
 
 if isfield(S,'end') && any(cellfun(@(x) isequal(x,0), {S.end}))
     unclosed = find(cellfun(@(x) isequal(x,0), {S.end}), 1);
-    error('MATL:parser', 'MATL error while parsing: <strong>%s</strong> statement has no matching <strong>]</strong>', S(unclosed).source)
+    error('MATL:parser', 'MATL error while parsing: %s%s%s statement has no matching <strong>]</strong>', strongBegin, S(unclosed).source, strongEnd)
 end
 
 end
diff --git a/matl_run.m b/matl_run.m
index 57e99a7..77fc4fd 100644
--- a/matl_run.m
+++ b/matl_run.m
@@ -1,4 +1,4 @@
-function matl_run(S, pOutFile, cOutFileNoExt, dbstopLines, isMatlab)
+function matl_run(S, pOutFile, cOutFileNoExt, dbstopLines, isMatlab, useTags)
 %
 % MATL runner and debugger: runs MATL code that has been compiled into MATLAB code. Catches MATLAB
 % errors and references them to the MATL statement that caused them.
@@ -48,7 +48,11 @@ function matl_run(S, pOutFile, cOutFileNoExt, dbstopLines, isMatlab)
     if ~isempty(ME.stack(h))
         k = ME.stack(h).line;
         n = find([S(:).compileLine]<=k, 1, 'last');
-        fprintf(2, 'MATL run-time error: The following MATLAB error refers to <a href="matlab: opentoline(''%s'', %i)">statement number %i:  %s</a>\n', pOutFile, n, n, S(n).source);
+        if useTags
+            fprintf(2, 'MATL run-time error: The following MATLAB error refers to <a href="matlab: opentoline(''%s'', %i)">statement number %i:  %s</a>\n', pOutFile, n, n, S(n).source);
+        else
+            fprintf(2, 'MATL run-time error: The following MATLAB error refers to statement number %i:  %s\n', n, S(n).source);
+        end
         fprintf(2, '---\n');
     else
         error('MATL:runner:internal', 'MATL internal error while running compiled file. More information follows');
diff --git a/preLit.mat b/preLit.mat
index bea1d36..faf2f2f 100644
Binary files a/preLit.mat and b/preLit.mat differ
diff --git a/preLit.txt b/preLit.txt
index ec4c0c9..68f5359 100644
--- a/preLit.txt
+++ b/preLit.txt
@@ -148,16 +148,8 @@ X8
 
 X9
 
-1	'shuffle'
-2	'default'
-3	'twister'
-4	'simdTwister'
-5	'combRecursive'
-6	'multFibonacci'
-10	'v5uniform'
-11	'v5normal'
-12	'v4'
-20	'seed'
+1	'%.16g '
+10	'seed'
 
 
 Y0