TextWrangler Files (black marking?)

Im wondering why some of my .lua files now have a black rectangle on top left side when you try to open them with Text Wrangler, some .lua files have them while others dont. Im just wondering what does that black rectangle means? Even projects I have as sample which I created them months ago now have that black rectangle on their .lua files but you can only see this black rectangle on the .lua files when you open or try to open them with Text Wrangler is there a meaning to this? [import]uid: 30314 topic_id: 18004 reply_id: 318004[/import]