.
Empty quote with attributes is not invalid, though, right? Because I mean a lot of people use that.
Got another one:
[img width=100]image[/img]
[quote author=authorname link=topic=144549.msg6597134#msg6597134 date=1446937214]
[center][color=magenta][size=14pt][glow=purple,2,300][b]text[/b][/glow][/size][/color][/center]
[/quote]