Text inside attachment bbcode never used

Using the "place inline" button you can add a [^blah blah] BBCode to your post. But the text inside that bbcode (the "blah blah" in my example) seems to be never used (at least I didn't find it anywhere except for the preview box in mcp). If that's supposed to be the name of the attachment, then it should be used as alternate text for inline images and/or as title of the attachment box ("Attachment: <name>"). Otherwise I'd be interested what the purpose of that text is.