Lark's Head. A type of knot. You've probably used it to attach tieline to the grommet in a drape, or when tying cable to a batten.
http://www.ehow.com/how_13480_make-larks-head.html
Aka Cow Hitch (Lanyard Hitch) if one free end.
http://www.animatedknots.com/cow/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Also known in our industry as a choke, especially with a polyester round sling (SpanSet).
http://www.ehow.com/how_13480_make-larks-head.html
Aka Cow Hitch (Lanyard Hitch) if one free end.
http://www.animatedknots.com/cow/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Also known in our industry as a choke, especially with a polyester round sling (SpanSet).