@@ -1151,8 +1151,11 @@
 function ct.parse_line(l, ctx, dest)
 	local newspan
 	local job = ctx.doc.stage.job
 	job:hook('line_read',ctx,l)
+	if l then
+		l = l:gsub("^ +","") -- trim leading spaces
+	end
 	if ctx.mode then
 		if ctx.mode.kind == 'code' then
 			if l and l:match '^~~~%s*$' then
 				job:hook('block_listing_end',ctx,ctx.mode.listing)
@@ -1267,16 +1270,9 @@
 					local args = ss.str.breakwords(ctx.doc.enc, l, 2, {escape=true})
 					if #args < 3 then
 						r.origin:fail('invalid syntax for resource %s', t.ref)
 					end
-					local mimebreak = function(s)
-						local wds = ss.str.split(ctx.doc.enc, s, '/', 1, {escape=true})
-						return wds
-					end
-					local mime = mimebreak(args[2]);
-					local mimeclasses = {
-						['application/svg+xml'] = 'image';
-					}
+					local mime = ss.mime(args[2]);
 					local class = mimeclasses[mime]
 					table.insert(srcs, {
 						mode = args[1];
 						mime = mime;
@@ -1284,11 +1280,15 @@
 						class = class or mime[1];
 					})
 				end
 				 --ideally move this into its own mimetype lib
-				local kind = r.props.as or srcs[1].class
-				r.class = kind
 				r.srcs = srcs
+				-- note that resources do not themselves have kinds. when a
+				-- document requests to insert a resource, the renderer must
+				-- iterate through the sources and find the first source it
+				-- is capable of emitting. this allows constructions like
+				-- emitting a video for HTML outputs, a photo for printers,
+				-- and a screenplay for tty/plaintext outputs.
 			end
 		end
 	end
 	ctx.doc.stage = nil