elide-head-headers-to-hide is a variable defined in `elide-head.el'.
Its value is

(("is free software[:;] you can redistribute it" . "\\(Boston, MA 0211\\(1-1307\\|0-1301\\), USA\\|If not, see \\)\\.") ("The Regents of the University of California\\. All rights reserved\\." . "SUCH DAMAGE\\.") ("Permission is hereby granted, free of charge" . "authorization from the X Consortium\\."))

Alist of regexps defining start end end of text to elide.

The cars of elements of the list are searched for in order. Text is
elided with an invisible overlay from the end of the line where the
first match is found to the end of the match for the corresponding

You can customize this variable.