Define LICENSE as dedication to public domain with CC0

CONTRIBUTING.md

@@ -0,0 +1,5 @@
+## Public Domain
+
+This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication. For more information, see [LICENSE.md](LICENSE.md).
+
+All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.

LICENSE.md

@@ -0,0 +1,32 @@
+As a work of the United States Government, this project is in the
+public domain within the United States.
+
+Additionally, we waive copyright and related rights in the work
+worldwide through the CC0 1.0 Universal public domain dedication.
+
+## CC0 1.0 Universal Summary
+
+This is a human-readable summary of the
+[Legal Code (read the full text)](https://creativecommons.org/publicdomain/zero/1.0/legalcode).
+
+### No Copyright
+
+The person who associated a work with this deed has dedicated the work to
+the public domain by waiving all of his or her rights to the work worldwide
+under copyright law, including all related and neighboring rights, to the
+extent allowed by law.
+
+You can copy, modify, distribute and perform the work, even for commercial
+purposes, all without asking permission.
+
+### Other Information
+
+In no way are the patent or trademark rights of any person affected by CC0,
+nor are the rights that other persons may have in the work or in how the
+work is used, such as publicity or privacy rights.
+
+Unless expressly stated otherwise, the person who associated a work with
+this deed makes no warranties about the work, and disclaims liability for
+all uses of the work, to the fullest extent permitted by applicable law.
+When using or citing the work, you should not imply endorsement by the
+author or the affirmer.

f_west.f

@@ -17,6 +17,12 @@ SUBROUTINE SHP_W3(DBHOB,HTTOT,GeoSUB,RFLW,RHFW)
 c                      Coefficients for NW TAPER Coop  April, 1994
 c                         (REGN  CD17.coe)
 c                       Copyright  J. W. Flewelling, 1994 
+c
+c              NOTE ON PUBLIC RELEASE: 
+c              Per the original author agreement, the 10-year proprietary 
+c              holding period has expired. This legacy code has been 
+c              released into the Public Domain by the maintaining agency.
+c***********************************************************************
 
       IMPLICIT DOUBLE PRECISION (A-H, O-Z) 
 

sf_zero.f

@@ -6,6 +6,11 @@ SUBROUTINE SF_ZERO(X1, F1, X2, F2, MODE, TOL)
 c      
 c           Code is Copyright by Language Systems.
 c           Source, object and executable MAY be distributed with SF_TEST.
+c
+c           HISTORICAL NOTE (2026 Review): Language Systems Corp. ceased 
+c           independent operations and was acquired by Fortner Research in 
+c           May 1996. This legacy file is retained under its original 
+c           permissive distribution terms ("MAY be distributed").
 
 c>> 1996       SZERO  JWF     Removed calls AMACH , MESS, SMESS and UMESS  
 c>> 1993-04-27 SZERO  Krogh   Additions for Conversion to C.