I forgot to mention that the current header does not indicate specifically that the code in the file is actually under the BSD license, it merely points to it and it implicit with its meaning:

! Copyright (c) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.

That is fixed to be in line with other common license notifications by providing the specific version of the license used, and a link to a copy of the license.