diff --git a/documentation/kernel-dev/kernel-dev-advanced.xml b/documentation/kernel-dev/kernel-dev-advanced.xml
index 5c76ed2391..37177966bf 100644
--- a/documentation/kernel-dev/kernel-dev-advanced.xml
+++ b/documentation/kernel-dev/kernel-dev-advanced.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <chapter id='kernel-dev-advanced'>
 <title>Working with Advanced Metadata (<filename>yocto-kernel-cache</filename>)</title>
diff --git a/documentation/kernel-dev/kernel-dev-common.xml b/documentation/kernel-dev/kernel-dev-common.xml
index c1c2d6d703..8e8a6dbed4 100644
--- a/documentation/kernel-dev/kernel-dev-common.xml
+++ b/documentation/kernel-dev/kernel-dev-common.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <chapter id='kernel-dev-common'>
 <title>Common Tasks</title>
diff --git a/documentation/kernel-dev/kernel-dev-concepts-appx.xml b/documentation/kernel-dev/kernel-dev-concepts-appx.xml
index 62c68527d2..0f2df2a629 100644
--- a/documentation/kernel-dev/kernel-dev-concepts-appx.xml
+++ b/documentation/kernel-dev/kernel-dev-concepts-appx.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <appendix id='kernel-dev-concepts-appx'>
 <title>Advanced Kernel Concepts</title>
diff --git a/documentation/kernel-dev/kernel-dev-customization.xsl b/documentation/kernel-dev/kernel-dev-customization.xsl
index 325b738e94..88bf7c678a 100644
--- a/documentation/kernel-dev/kernel-dev-customization.xsl
+++ b/documentation/kernel-dev/kernel-dev-customization.xsl
@@ -1,4 +1,6 @@
 <?xml version='1.0'?>
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
+
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns="http://www.w3.org/1999/xhtml" xmlns:fo="http://www.w3.org/1999/XSL/Format" version="1.0">
 
   <xsl:import href="http://downloads.yoctoproject.org/mirror/docbook-mirror/docbook-xsl-1.76.1/xhtml/docbook.xsl" />
diff --git a/documentation/kernel-dev/kernel-dev-faq.xml b/documentation/kernel-dev/kernel-dev-faq.xml
index c3a20465a0..d76f0a4e32 100644
--- a/documentation/kernel-dev/kernel-dev-faq.xml
+++ b/documentation/kernel-dev/kernel-dev-faq.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <appendix id='kernel-dev-faq'>
 <title>Kernel Development FAQ</title>
diff --git a/documentation/kernel-dev/kernel-dev-intro.xml b/documentation/kernel-dev/kernel-dev-intro.xml
index 4e4fd282a5..7c1ea0e510 100644
--- a/documentation/kernel-dev/kernel-dev-intro.xml
+++ b/documentation/kernel-dev/kernel-dev-intro.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <chapter id='kernel-dev-intro'>
 <title>Introduction</title>
diff --git a/documentation/kernel-dev/kernel-dev-maint-appx.xml b/documentation/kernel-dev/kernel-dev-maint-appx.xml
index b825ae7ea5..3d9c7c66fd 100644
--- a/documentation/kernel-dev/kernel-dev-maint-appx.xml
+++ b/documentation/kernel-dev/kernel-dev-maint-appx.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <appendix id='kernel-dev-maint-appx'>
 <title>Kernel Maintenance</title>
diff --git a/documentation/kernel-dev/kernel-dev-style.css b/documentation/kernel-dev/kernel-dev-style.css
index 9c01aa7983..fc6fbb8de1 100644
--- a/documentation/kernel-dev/kernel-dev-style.css
+++ b/documentation/kernel-dev/kernel-dev-style.css
@@ -1,4 +1,7 @@
 /*
+
+   SPDX-License-Identifier: CC-BY-2.0-UK
+
    Generic XHTML / DocBook XHTML CSS Stylesheet.
 
    Browser wrangling and typographic design by
diff --git a/documentation/kernel-dev/kernel-dev.xml b/documentation/kernel-dev/kernel-dev.xml
index 998fe41415..887ff836f1 100755
--- a/documentation/kernel-dev/kernel-dev.xml
+++ b/documentation/kernel-dev/kernel-dev.xml
@@ -1,6 +1,7 @@
 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
 [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
+<!--SPDX-License-Identifier: CC-BY-2.0-UK-->
 
 <book id='kernel-dev' lang='en'
       xmlns:xi="http://www.w3.org/2003/XInclude"