some files have unspecified License and Copyright

[perkelix]

As per 10.3.0:

$ licensecheck . | grep -v License
./.clangd: *No copyright* UNKNOWN
./BUILDING.md: *No copyright* UNKNOWN
./Makefile: *No copyright* UNKNOWN
./Makefile.inc: *No copyright* UNKNOWN
./README.md: *No copyright* UNKNOWN
./config-null.mk: *No copyright* UNKNOWN
./configure: *No copyright* UNKNOWN
./iconfig.mk: *No copyright* UNKNOWN

$ licensecheck -r compat | grep -v License
compat/arc4random.h: UNKNOWN
compat/chacha_private.h: *No copyright* UNKNOWN
compat/consttime_memequal.h: *No copyright* UNKNOWN
compat/queue.h: *No copyright* UNKNOWN
compat/crypt/md5.c: *No copyright* Public domain
compat/crypt/md5.h: *No copyright* Public domain

$ licensecheck -r hooks | grep -v License
hooks/01-test: *No copyright* UNKNOWN
hooks/10-wpa_supplicant: *No copyright* UNKNOWN
hooks/15-timezone: *No copyright* UNKNOWN
hooks/20-resolv.conf: *No copyright* UNKNOWN
hooks/29-lookup-hostname: *No copyright* UNKNOWN
hooks/30-hostname.in: *No copyright* UNKNOWN
hooks/50-dhcpcd-compat: *No copyright* UNKNOWN
hooks/50-ntp.conf: *No copyright* UNKNOWN
hooks/50-timesyncd.conf: *No copyright* UNKNOWN
hooks/50-yp.conf: *No copyright* UNKNOWN
hooks/50-ypbind.in: *No copyright* UNKNOWN
hooks/Makefile: *No copyright* UNKNOWN
hooks/dhcpcd-run-hooks.in: *No copyright* UNKNOWN

$ licensecheck -r src | grep -v License
src/GNUmakefile: *No copyright* UNKNOWN
src/Makefile: *No copyright* UNKNOWN
src/dhcpcd-definitions-small.conf: UNKNOWN
src/dhcpcd-definitions.conf: UNKNOWN
src/dhcpcd.conf: *No copyright* UNKNOWN
src/genembedc: *No copyright* UNKNOWN
src/genembedh: *No copyright* UNKNOWN
src/queue.h: *No copyright* UNKNOWN
src/dev/Makefile: *No copyright* UNKNOWN

$ licensecheck -r tests | grep -v License
tests/Makefile: *No copyright* UNKNOWN
tests/crypt/GNUmakefile: *No copyright* UNKNOWN
tests/crypt/Makefile: *No copyright* UNKNOWN
tests/crypt/README.md: *No copyright* UNKNOWN
tests/eloop-bench/Makefile: *No copyright* UNKNOWN
tests/eloop-bench/README.md: *No copyright* UNKNOWN

$ licensecheck -r vendor | grep -v License
vendor/README.md: *No copyright* UNKNOWN

The rest of the source code seemingly checks as covered by the BSD-2-Clause-NetBSD and/or BSD-2-clause.

Using the SPDX-License-Identifier format is highly recommended. A shell script example using the GPL:

# Copyright: © 2003-2025 Martin-Éric Racine <email>
# SPDX-License-Identifier: GPL-2.0-or-later