Posted by Wayne Parham on October 01, 2003 at 01:32:54

In Reply to: Re: You've got mail! posted by andreas@kemi.dtu.dk on October 01, 2003 at 01:09:20:

That's right - The horn is formed from the expansion from the apex of the corner outwards.

There's more information about them in the post called "Cornerhorns," which describes this configuration in some detail and also includes a link to a list of posts at the end.