Taken from archlinux repository
--- /dev/null	2020-07-07 05:09:03.382036815 +0000
+++ ./LICENSE	2020-07-07 05:10:26.439250715 +0000
@@ -0,0 +1,24 @@
+Copyright 1992-2006 HaL Computer Systems, Inc.,
+O'Reilly & Associates, Inc., ArborText, Inc., Fujitsu Software
+Corporation, Norman Walsh, Sun Microsystems, Inc., and the
+Organization for the Advancement of Structured Information
+Standards (OASIS).
+
+See also http://docbook.org/specs/
+
+Permission to use, copy, modify and distribute the DocBook XML DTD
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