@@ -124,16 +124,51 @@
 			ctx.sec = doc:mksec() -- toplevel section
 			ctx.sec.origin = ctx:clone()
 		end;
 		ref = function(self,id)
+			if self.invocation then
+				-- allow IDs to contain template substitutions by mimicking the [#n] syntax
+				id = id:gsub('%b[]', function(sp)
+					-- should indirection be allowed here? TODO
+					if sp:sub(2,2) == '#' then
+						local n = tonumber(sp:sub(3,-2))
+						if n == nil then
+							self:fail('invalid template substitution “%s” in ID “%s”', sp, id)
+						end
+						local arg = self.invocation.args[n]
+						if arg == nil then
+							self:fail('template instantiation requires at least %u arguments (in ID “%s”)',n,id)
+						end
+						return arg
+					else return sp end
+				end)
+
+			end
 			if not id:find'%.' then
 				local rid = self.sec.refs[id]
-				if self.sec.refs[id] then
-					return self.sec.refs[id], id, self.sec
-				else self:fail("no such ref %s in current section", id or '') end
+				if rid then
+					return rid, id, self.sec
+				end
+
+				--nothing in the current section, but this ID could be looked up in the context of a macro expansion. if so, check section of the site of invocation as well
+				if self.invocation then
+					rid = self.invocation.origin:ref(id)
+					if rid then
+						return rid, id, self.invocation.origin.sec
+					end
+				end
+
+				self:fail("no such ref %s in current section", id or '')
 			else
 				local sec, ref = string.match(id, "(.-)%.(.+)")
-				local s = self.doc.sections[sec]
+				local s
+				if sec == '' then
+					if self.invocation == nil then
+						self:fail('site-of-invocation IDs can only be dereferenced in a macro expansion (offending ID: “%s”)', id)
+					end
+					s = self.invocation.origin.sec
+				end
+				s = s or self.doc.sections[sec]
 				if not s then -- fall back on inheritance tree
 					for i, p in ipairs(self.doc.parents) do
 						if p.sections[sec] then
 							s = p.sections[sec]
@@ -1298,17 +1333,21 @@
 			args = argv;
 		}
 	end)};
 	{seq='&', fn=blockwrap(function(s,c)
-		local id, cap = s:match('^&([^%s]+)%s*(.-)%s*$')
+		local mode, id, cap = s:match('^&([-+]?)([^%s]+)%s*(.-)%s*$')
 		if id == nil or id == '' then
 			c:fail 'malformed embed block'
 		end
-		if cap == '' then cap = nil end
+		if     cap  == ''  then cap = nil end
+		if     mode == '-' then mode = 'closed'
+		elseif mode == '+' then mode = 'open'
+		                   else mode = 'inline' end
 		return {
 			kind = 'embed';
 			ref = id;
 			cap = cap;
+			mode = mode;
 		}
 	end)};
 	{fn = insert_paragraph};
 }