diff --git a/.b4-config b/.b4-config
index 371e3e9c..99d0361c 100644
--- a/.b4-config
+++ b/.b4-config
@@ -1,2 +1,4 @@
+# SPDX-License-Identifier: CC0-1.0
+
 [b4]
   send-series-to = libcamera-devel@lists.libcamera.org
diff --git a/Documentation/mainpage.dox b/Documentation/mainpage.dox
index 99e67e7a..b651788e 100644
--- a/Documentation/mainpage.dox
+++ b/Documentation/mainpage.dox
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC-BY-SA-4.0
+
 /**
 \if internal
 \mainpage libcamera internal API reference
diff --git a/Documentation/thread-safety.dox b/Documentation/thread-safety.dox
index df4c457c..0bc02bfc 100644
--- a/Documentation/thread-safety.dox
+++ b/Documentation/thread-safety.dox
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC-BY-SA-4.0
+
 /**
  * \page thread-safety Reentrancy and Thread-Safety
  *
diff --git a/src/libcamera/pipeline/virtual/README.md b/src/libcamera/pipeline/virtual/README.md
index a9f39c15..0b2f03d8 100644
--- a/src/libcamera/pipeline/virtual/README.md
+++ b/src/libcamera/pipeline/virtual/README.md
@@ -1,3 +1,5 @@
+<!-- SPDX-License-Identifier: CC-BY-SA-4.0 -->
+
 # Virtual Pipeline Handler
 
 Virtual pipeline handler emulates fake external camera(s) for testing.
@@ -9,6 +11,7 @@ Virtual pipeline handler emulates fake external camera(s) for testing.
   `share/libcamera/pipeline/virtual/virtual.yaml`.
 
 ### Config File Format
+
 The config file contains the information about cameras' properties to register.
 The config file should be a yaml file with dictionary of the cameraIds
 associated with their properties as top level. The default value will be applied
diff --git a/src/libcamera/pipeline/virtual/data/meson.build b/src/libcamera/pipeline/virtual/data/meson.build
index ce63f9a2..0cade65b 100644
--- a/src/libcamera/pipeline/virtual/data/meson.build
+++ b/src/libcamera/pipeline/virtual/data/meson.build
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 install_data('virtual.yaml',
              install_dir : pipeline_data_dir / 'virtual',
              install_tag : 'runtime',
diff --git a/src/libcamera/software_isp/TODO.md b/src/libcamera/software_isp/TODO.md
index 036cf2b7..0f27da2d 100644
--- a/src/libcamera/software_isp/TODO.md
+++ b/src/libcamera/software_isp/TODO.md
@@ -1,3 +1,5 @@
+<!-- SPDX-License-Identifier: CC0-1.0 -->
+
 # Software ISP TODO list
 
 This file contains the TODO list for the software ISP.
diff --git a/utils/tuning/config-example.yaml b/utils/tuning/config-example.yaml
index 5593eaef..316ced08 100644
--- a/utils/tuning/config-example.yaml
+++ b/utils/tuning/config-example.yaml
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: CC0-1.0
 general:
   disable: []
   plot: []
diff --git a/utils/tuning/libtuning/ctt_colors.py b/utils/tuning/libtuning/ctt_colors.py
index cb4d236b..7e9ba646 100644
--- a/utils/tuning/libtuning/ctt_colors.py
+++ b/utils/tuning/libtuning/ctt_colors.py
@@ -1,4 +1,9 @@
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (C) 2023, Raspberry Pi Ltd
+#
 # Program to convert from RGB to LAB color space
+
 def RGB_to_LAB(RGB):  # where RGB is a 1x3 array.   e.g RGB = [100, 255, 230]
     num = 0
     XYZ = [0, 0, 0]
diff --git a/utils/tuning/requirements.txt b/utils/tuning/requirements.txt
index 3705769b..8e14ce09 100644
--- a/utils/tuning/requirements.txt
+++ b/utils/tuning/requirements.txt
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: CC0-1.0
 coloredlogs
 matplotlib
 numpy