@@ -25,14 +25,20 @@
 	return new
 end
 
 local function
-main(input, output, log, mode, vars)
+main(input, output, log, mode, suggestions, vars)
 	local doc = ct.parse(input.stream, input.src, mode)
 	input.stream:close()
 	if mode['parse:show-tree'] then
 		log:write(dump(doc))
 	end
+
+	-- the document has now had a chance to give its say; if it hasn't specified
+	-- any modes of its own, we now merge in the 'weak modes' (suggestions)
+	for k,v in pairs(suggestions) do
+		if not mode[k] then mode[k] = v end
+	end
 
 	if not mode['render:format'] then
 		error 'what output format should i translate the input to?'
 	end
@@ -54,8 +60,9 @@
 	doc.stage = {
 		kind = 'render';
 		format = mode['render:format'];
 		mode = mode;
+		suggestions = suggestions;
 	}
 
 	output:write(ct.render[mode['render:format']](doc, render_opts))
 	return 0
@@ -63,23 +70,30 @@
 
 local inp,outp,log = io.stdin, io.stdout, io.stderr
 
 local function entry_cli()
-	local mode, vars, input = default_mode, {}, {
+	local suggestions, vars, input = default_mode, {}, {
 		stream = inp;
 		src = {
 			file = '(stdin)';
 		}
 	}
+
+	local mode = {}
 
 	local optnparams = function(o)
 		local param_opts = {
 			out = 1;
 			log = 1;
 			define = 2; -- key value
+
 			['mode-set'] = 1;
 			['mode-clear'] = 1;
 			mode = 2;
+
+			['mode-set-weak'] = 1;
+			['mode-clear-weak'] = 1;
+			['mode-weak'] = 2;
 		}
 		return param_opts[o] or 0
 	end
 
@@ -88,10 +102,11 @@
 		l = 'log';
 		d = 'define';
 		V = 'version';
 		h = 'help';
-		y = 'mode-set', n = 'mode-clear';
-		m = 'mode';
+		y = 'mode-set',   Y = 'mode-set-weak';
+		n = 'mode-clear', N = 'mode-clear-weak';
+		m = 'mode',       M = 'mode-weak';
 	}
 
 	local checkmodekey = function(key)
 		if not key:match '[^:]+:.+' then
@@ -120,8 +135,12 @@
 		end;
 		mode = function(key,value) mode[checkmodekey(key)] = value end;
 		['mode-set'] = function(key) mode[checkmodekey(key)] = true end;
 		['mode-clear'] = function(key) mode[checkmodekey(key)] = false end;
+
+		['mode-weak'] = function(key,value) suggestions[checkmodekey(key)] = value end;
+		['mode-set-weak'] = function(key) suggestions[checkmodekey(key)] = true end;
+		['mode-clear-weak'] = function(key) suggestions[checkmodekey(key)] = false end;
 	}
 
 	local args = {}
 	local keepParsing = true
@@ -175,9 +194,9 @@
 		input.stream = file
 		input.src.file = args[1]
 	end
 
-	return main(input, outp, log, mode, vars)
+	return main(input, outp, log, mode, suggestions, vars)
 end
 
 local ok, e = pcall(entry_cli)
 -- local ok, e = true, entry_cli()