treewide: Add nice GPL-3.0-or-later license header

This change also ensures that this repo is reuse-3.0 compliant.

1 files changed, 25 insertions, 13 deletions

diff --git a/notes/gpg_keys.md b/notes/gpg_keys.md
index 39602e3b..4a6fb5d1 100644
--- a/notes/gpg_keys.md
+++ b/notes/gpg_keys.md
@@ -1,3 +1,15 @@
+<!--
+nixos-config - My current NixOS configuration
+
+Copyright (C) 2025 Benedikt Peetz <benedikt.peetz@b-peetz.de>
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This file is part of my nixos-config.
+
+You should have received a copy of the License along with this program.
+If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.
+-->
+
 # How to add a comment to gpg keys
 
 Export it as follows:
@@ -11,38 +23,38 @@ or add it manually, the supported options include (RFC4880):
 - "Version", which states the OpenPGP implementation and version
   used to encode the message.
 
-- "Comment", a user-defined comment.  OpenPGP defines all text to
-  be in UTF-8.  A comment may be any UTF-8 string.  However, the
+- "Comment", a user-defined comment. OpenPGP defines all text to
+  be in UTF-8. A comment may be any UTF-8 string. However, the
   whole point of armoring is to provide seven-bit-clean data.
   Consequently, if a comment has characters that are outside the
   US-ASCII range of UTF, they may very well not survive transport.
 
-- "MessageID", a 32-character string of printable characters.  The
+- "MessageID", a 32-character string of printable characters. The
   string must be the same for all parts of a multi-part message
-  that uses the "PART X" Armor Header.  MessageID strings should be
+  that uses the "PART X" Armor Header. MessageID strings should be
   unique enough that the recipient of the mail can associate all
-  the parts of a message with each other.  A good checksum or
+  the parts of a message with each other. A good checksum or
   cryptographic hash function is sufficient.
 
   The MessageID SHOULD NOT appear unless it is in a multi-part
-  message.  If it appears at all, it MUST be computed from the
+  message. If it appears at all, it MUST be computed from the
   finished (encrypted, signed, etc.) message in a deterministic
-  fashion, rather than contain a purely random value.  This is to
+  fashion, rather than contain a purely random value. This is to
   allow the legitimate recipient to determine that the MessageID
   cannot serve as a covert means of leaking cryptographic key
   information.
 
 - "Hash", a comma-separated list of hash algorithms used in this
-  message.  This is used only in cleartext signed messages.
+  message. This is used only in cleartext signed messages.
 
 - "Charset", a description of the character set that the plaintext
-  is in.  Please note that OpenPGP defines text to be in UTF-8.  An
+  is in. Please note that OpenPGP defines text to be in UTF-8. An
   implementation will get best results by translating into and out
-  of UTF-8.  However, there are many instances where this is easier
-  said than done.  Also, there are communities of users who have no
+  of UTF-8. However, there are many instances where this is easier
+  said than done. Also, there are communities of users who have no
   need for UTF-8 because they are all happy with a character set
-  like ISO Latin-5 or a Japanese character set.  In such instances,
+  like ISO Latin-5 or a Japanese character set. In such instances,
   an implementation MAY override the UTF-8 default by using this
-  header key.  An implementation MAY implement this key and any
+  header key. An implementation MAY implement this key and any
   translations it cares to; an implementation MAY ignore it and
   assume all text is UTF-8.