diff --git a/.codecov.yml b/.codecov.yml
index 7b6eecb66e..be8ab11829 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 codecov:
   branch: develop
   ci:
diff --git a/.ddev/config.yaml b/.ddev/config.yaml
index 26cba10525..28dd56a88b 100644
--- a/.ddev/config.yaml
+++ b/.ddev/config.yaml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 name: my-friendica
 type: php
 docroot: ""
diff --git a/.editorconfig b/.editorconfig
index 610409143b..57445d869c 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # editorconfig tool configuration
 # see http://editorconfig.org for docs
 
diff --git a/.gitattributes b/.gitattributes
index 18ba9e0758..915c608e7a 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1,6 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # Disable LF normalization for all files
 * -text
diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index 8e3ff067f6..605e11e136 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 ---
 name: Bug report
 about: Create a report to help us improve
diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
index 7bdd4f066c..70ae203464 100644
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 blank_issues_enabled: true
 contact_links:
   - name: Friendica Community Support
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
index e65d397099..ed0a7f0c4e 100644
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 ---
 name: Feature request
 about: Suggest an idea for this project
diff --git a/.github/ISSUE_TEMPLATE/question.md b/.github/ISSUE_TEMPLATE/question.md
index 86df437339..8eca53f4c7 100644
--- a/.github/ISSUE_TEMPLATE/question.md
+++ b/.github/ISSUE_TEMPLATE/question.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 ---
 name: Question / Support
 about: Select this if you have a question 
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index f33a02cd16..9719a47b02 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # To get started with Dependabot version updates, you'll need to specify which
 # package ecosystems to update and where the package manifests are located.
 # Please see the documentation for more information:
diff --git a/.gitignore b/.gitignore
index bbc83a55df..ce397308bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 favicon.*
 /.htconfig.php
 /.htpreconfig.php
diff --git a/.htaccess-dist b/.htaccess-dist
index c5c1b5b716..bb53517fc3 100644
--- a/.htaccess-dist
+++ b/.htaccess-dist
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 # This file is meant to be copied to ".htaccess" on Apache-powered web servers.
 # The created .htaccess file can be edited manually and will not be overwritten by Friendica updates.
 
diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index 9345ee617e..64aeb6cf6c 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 <?php
 /**
  * @copyright Copyright (C) 2010-2024, the Friendica project
diff --git a/.php_cs.dist b/.php_cs.dist
index 1d7056bdc1..a78ed2a959 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
+-->
+
 <?php
 
 declare(strict_types=1);
diff --git a/.tx/config b/.tx/config
index 32bcaf482d..ced61f382d 100644
--- a/.tx/config
+++ b/.tx/config
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 [main]
 host = https://api.transifex.com
 
diff --git a/.woodpecker/.code_standards_check.yml b/.woodpecker/.code_standards_check.yml
index 0c951d7018..30938f15fe 100644
--- a/.woodpecker/.code_standards_check.yml
+++ b/.woodpecker/.code_standards_check.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 steps:
   restore_cache:
     image: meltwater/drone-cache:dev
diff --git a/.woodpecker/.continuous-deployment.yml b/.woodpecker/.continuous-deployment.yml
index 4ce8a70930..eff4ae0cff 100644
--- a/.woodpecker/.continuous-deployment.yml
+++ b/.woodpecker/.continuous-deployment.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 depends_on:
   - phpunit
   - code_standards_check
diff --git a/.woodpecker/.database_checks.yml b/.woodpecker/.database_checks.yml
index 390df0a6be..6bde5b281e 100644
--- a/.woodpecker/.database_checks.yml
+++ b/.woodpecker/.database_checks.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 matrix:
   include:
     - PHP_MAJOR_VERSION: 8.2
diff --git a/.woodpecker/.license_check.yml b/.woodpecker/.license_check.yml
index e7545f5f43..985a03cd47 100644
--- a/.woodpecker/.license_check.yml
+++ b/.woodpecker/.license_check.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 steps:
   check:
     image: friendicaci/php-cs
diff --git a/.woodpecker/.messages.po_check.yml b/.woodpecker/.messages.po_check.yml
index d568aa49fe..8df12b93ce 100644
--- a/.woodpecker/.messages.po_check.yml
+++ b/.woodpecker/.messages.po_check.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 steps:
   build_xgettext:
     image: friendicaci/transifex
diff --git a/.woodpecker/.phpunit.yml b/.woodpecker/.phpunit.yml
index 7141ef8943..86abe6326d 100644
--- a/.woodpecker/.phpunit.yml
+++ b/.woodpecker/.phpunit.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 matrix:
   include:
     - PHP_MAJOR_VERSION: 7.4
diff --git a/.woodpecker/.releaser.yml b/.woodpecker/.releaser.yml
index 175ab7d514..0c7caac009 100644
--- a/.woodpecker/.releaser.yml
+++ b/.woodpecker/.releaser.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 depends_on:
   - phpunit
   - code_standards_check
diff --git a/CHANGELOG.license b/CHANGELOG.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/CHANGELOG.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/CONTRIBUTING.md.license b/CONTRIBUTING.md.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/CONTRIBUTING.md.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/CREDITS.txt.license b/CREDITS.txt.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/CREDITS.txt.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/Doxyfile.license b/Doxyfile.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/Doxyfile.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/README.md.license b/README.md.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/README.md.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/REUSE.toml.license b/REUSE.toml.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/REUSE.toml.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/VERSION.license b/VERSION.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/VERSION.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/Vagrantfile.license b/Vagrantfile.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/Vagrantfile.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/bin/.htaccess.license b/bin/.htaccess.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/bin/.htaccess.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/bin/composer.phar.license b/bin/composer.phar.license
new file mode 100644
index 0000000000..57e47667a3
--- /dev/null
+++ b/bin/composer.phar.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2012 Nils Adermann, Jordi Boggiano
+
+SPDX-License-Identifier: MIT
diff --git a/bin/console b/bin/console
index 79b6c8d3b9..6d0d088732 100755
--- a/bin/console
+++ b/bin/console
@@ -1,5 +1,9 @@
 #!/bin/bash
 
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 dir=$(cd "${0%[/\\]*}" > /dev/null; pwd)
 
 if [[ -d /proc/cygdrive && $(which php) == $(readlink -n /proc/cygdrive)/* ]]; then
diff --git a/bin/console.bat b/bin/console.bat
index 06c41a03e6..438c4da0b2 100755
--- a/bin/console.bat
+++ b/bin/console.bat
@@ -1,3 +1,7 @@
+REM SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+REM
+REM SPDX-License-Identifier: CC0-1.0
+
 @echo OFF
 :: in case DelayedExpansion is on and a path contains !
 setlocal DISABLEDELAYEDEXPANSION
diff --git a/bin/run_xgettext.sh b/bin/run_xgettext.sh
index 254fc50699..1375f2b276 100755
--- a/bin/run_xgettext.sh
+++ b/bin/run_xgettext.sh
@@ -1,4 +1,9 @@
 #!/bin/bash
+
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
 set -eo pipefail
 
 function resolve {
diff --git a/security.txt.license b/security.txt.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/security.txt.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/translations.txt.license b/translations.txt.license
new file mode 100644
index 0000000000..8a315c7ab7
--- /dev/null
+++ b/translations.txt.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+
+SPDX-License-Identifier: CC0-1.0