fullmetaphone copyright and credits
===================================

The package as a whole
    Copyright (C) 2026 Anil Kumar Goyal and Atharv Tyagi.
    Licensed under the GNU General Public License, version 3.

Algorithms
    Metaphone and Double Metaphone were designed by Lawrence Philips.
    Metaphone was published in Computer Language 7(12), 1990.
    Double Metaphone was published, with C++ code, in C/C++ Users
    Journal 18(6), June 2000.

R/double_metaphone.R
    The rules are a translation into R of the C implementation of Double
    Metaphone by Maurice Aubrey (Copyright 2000, Maurice Aubrey), which
    is based on Lawrence Philips' C++ code and includes bug fixes by
    Kevin Atkinson. Aubrey's code is distributed under the same terms as
    Perl, which allow redistribution under the GNU General Public
    License. The same C code is used in the R package 'PGRdup'
    (Copyright ICAR-NBPGR, GPL-2 | GPL-3) by J. Aravind, J. Radhamani,
    Kalyani Srinivasan, B. Ananda Subhash and co-authors,
    which brought Double Metaphone to R and inspired this package.
    Unlike that code, this version does not cut the codes to four
    characters.

R/metaphone.R
    The rules are a translation into R of the Metaphone class in Apache
    Commons Codec.
    Copyright The Apache Software Foundation.
    Licensed under the Apache License, Version 2.0, which is compatible
    with the GNU General Public License, version 3.
    https://www.apache.org/licenses/LICENSE-2.0

data/us_surnames.rda
    The 5000 most common surnames from "Frequently Occurring Surnames
    from the 2010 Census" by the United States Census Bureau.
    https://www.census.gov/topics/population/genealogy/data/2010_surnames.html
    Works of the United States Government are in the public domain.

tests/testthat/testdata/commons_double_metaphone.csv and the expected
codes in tests/testthat/test-metaphone.R
    Taken from the test suite of Apache Commons Codec
    (DoubleMetaphone2Test.java and MetaphoneTest.java).
    Copyright The Apache Software Foundation.
    Licensed under the Apache License, Version 2.0.