diff --git a/docs/FAQ.md b/docs/FAQ.md
index 2ef9e6c2b..7a941e604 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -4,6 +4,8 @@ nav_order: 1
permalink: /faq
---
+{% include deprecation.html %}
+
# FAQ
## Why does Dendrite exist?
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 8e72da971..786735c5a 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -1,3 +1,6 @@
+
+{% include deprecation.html %}
+
# Installation
Please note that new installation instructions can be found
diff --git a/docs/_includes/deprecation.html b/docs/_includes/deprecation.html
new file mode 100644
index 000000000..cb7073b1a
--- /dev/null
+++ b/docs/_includes/deprecation.html
@@ -0,0 +1,6 @@
+{: .warning-title }
+> This documentation is out of date!
+>
+> This documentation site is for the versions of Dendrite maintained by the Matrix.org Foundation (github.com/matrix-org/dendrite), available under the Apache 2.0 licence.
+>
+> If you are interested in the documentation for a later version of Dendrite, please refer to https://element-hq.github.io/dendrite/.
\ No newline at end of file
diff --git a/docs/_sass/custom/custom.scss b/docs/_sass/custom/custom.scss
deleted file mode 100644
index 8a5ed3d8d..000000000
--- a/docs/_sass/custom/custom.scss
+++ /dev/null
@@ -1,3 +0,0 @@
-footer.site-footer {
- opacity: 10%;
-}
\ No newline at end of file
diff --git a/docs/administration.md b/docs/administration.md
index 08ad7803e..15add5b32 100644
--- a/docs/administration.md
+++ b/docs/administration.md
@@ -5,6 +5,8 @@ nav_order: 4
permalink: /administration
---
+{% include deprecation.html %}
+
# Administration
This section contains documentation on managing your existing Dendrite deployment.
diff --git a/docs/administration/1_createusers.md b/docs/administration/1_createusers.md
index cbdccd18b..7052004d8 100644
--- a/docs/administration/1_createusers.md
+++ b/docs/administration/1_createusers.md
@@ -5,6 +5,8 @@ permalink: /administration/createusers
nav_order: 1
---
+{% include deprecation.html %}
+
# Creating user accounts
User accounts can be created on a Dendrite instance in a number of ways.
diff --git a/docs/administration/2_registration.md b/docs/administration/2_registration.md
index 66949f2ca..8599e614c 100644
--- a/docs/administration/2_registration.md
+++ b/docs/administration/2_registration.md
@@ -5,6 +5,8 @@ permalink: /administration/registration
nav_order: 2
---
+{% include deprecation.html %}
+
# Enabling registration
Enabling registration allows users to register their own user accounts on your
diff --git a/docs/administration/3_presence.md b/docs/administration/3_presence.md
index 858025370..22c22c9e2 100644
--- a/docs/administration/3_presence.md
+++ b/docs/administration/3_presence.md
@@ -5,6 +5,8 @@ permalink: /administration/presence
nav_order: 3
---
+{% include deprecation.html %}
+
# Enabling presence
Dendrite supports presence, which allows you to send your online/offline status
diff --git a/docs/administration/4_adminapi.md b/docs/administration/4_adminapi.md
index 40d02622b..1e840d621 100644
--- a/docs/administration/4_adminapi.md
+++ b/docs/administration/4_adminapi.md
@@ -5,6 +5,8 @@ nav_order: 4
permalink: /administration/adminapi
---
+{% include deprecation.html %}
+
# Supported admin APIs
Dendrite supports, at present, a very small number of endpoints that allow
diff --git a/docs/administration/5_optimisation.md b/docs/administration/5_optimisation.md
index 57b7924d3..9bcfb658a 100644
--- a/docs/administration/5_optimisation.md
+++ b/docs/administration/5_optimisation.md
@@ -6,6 +6,8 @@ nav_order: 5
permalink: /administration/optimisation
---
+{% include deprecation.html %}
+
# Optimise your installation
Now that you have Dendrite running, the following tweaks will improve the reliability
diff --git a/docs/administration/6_troubleshooting.md b/docs/administration/6_troubleshooting.md
index 5f11f9931..27916b64c 100644
--- a/docs/administration/6_troubleshooting.md
+++ b/docs/administration/6_troubleshooting.md
@@ -5,6 +5,8 @@ nav_order: 6
permalink: /administration/troubleshooting
---
+{% include deprecation.html %}
+
# Troubleshooting
If your Dendrite installation is acting strangely, there are a few things you should
diff --git a/docs/development.md b/docs/development.md
index cf296fb53..2ed616c31 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -4,6 +4,10 @@ has_children: true
permalink: /development
---
+{% include deprecation.html %}
+
+{% include deprecation.html %}
+
# Development
This section contains documentation that may be useful when helping to develop
diff --git a/docs/development/CONTRIBUTING.md b/docs/development/CONTRIBUTING.md
index caab1e749..0529071d1 100644
--- a/docs/development/CONTRIBUTING.md
+++ b/docs/development/CONTRIBUTING.md
@@ -5,6 +5,8 @@ nav_order: 1
permalink: /development/contributing
---
+{% include deprecation.html %}
+
# Contributing to Dendrite
Everyone is welcome to contribute to Dendrite! We aim to make it as easy as
diff --git a/docs/development/PROFILING.md b/docs/development/PROFILING.md
index dc4eca7b7..d91416285 100644
--- a/docs/development/PROFILING.md
+++ b/docs/development/PROFILING.md
@@ -5,6 +5,8 @@ nav_order: 4
permalink: /development/profiling
---
+{% include deprecation.html %}
+
# Profiling Dendrite
If you are running into problems with Dendrite using excessive resources (e.g. CPU or RAM) then you can use the profiler to work out what is happening.
diff --git a/docs/development/coverage.md b/docs/development/coverage.md
index 1b15f71a2..3ae92c9c9 100644
--- a/docs/development/coverage.md
+++ b/docs/development/coverage.md
@@ -5,6 +5,8 @@ nav_order: 3
permalink: /development/coverage
---
+{% include deprecation.html %}
+
## Running unit tests with coverage enabled
Running unit tests with coverage enabled can be done with the following commands, this will generate a `integrationcover.log`
diff --git a/docs/development/sytest.md b/docs/development/sytest.md
index 2f681f3e5..274412bac 100644
--- a/docs/development/sytest.md
+++ b/docs/development/sytest.md
@@ -5,6 +5,8 @@ nav_order: 2
permalink: /development/sytest
---
+{% include deprecation.html %}
+
# SyTest
Dendrite uses [SyTest](https://github.com/matrix-org/sytest) for its
diff --git a/docs/index.md b/docs/index.md
index 64836152c..d60702265 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -3,6 +3,8 @@ layout: home
nav_exclude: true
---
+{% include deprecation.html %}
+
# Dendrite
Dendrite is a second-generation Matrix homeserver written in Go! Following the microservice
diff --git a/docs/installation.md b/docs/installation.md
index c38a6dbb2..142d2a689 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -5,6 +5,8 @@ nav_order: 2
permalink: /installation
---
+{% include deprecation.html %}
+
# Installation
This section contains documentation on installing a new Dendrite deployment.
diff --git a/docs/installation/1_planning.md b/docs/installation/1_planning.md
index e113ca2d3..9174d3726 100644
--- a/docs/installation/1_planning.md
+++ b/docs/installation/1_planning.md
@@ -5,6 +5,8 @@ nav_order: 1
permalink: /installation/planning
---
+{% include deprecation.html %}
+
# Planning your installation
## Database
diff --git a/docs/installation/2_domainname.md b/docs/installation/2_domainname.md
index d86a664cb..f658b0f74 100644
--- a/docs/installation/2_domainname.md
+++ b/docs/installation/2_domainname.md
@@ -5,6 +5,8 @@ nav_order: 2
permalink: /installation/domainname
---
+{% include deprecation.html %}
+
# Setting up the domain
Every Matrix server deployment requires a server name which uniquely identifies it. For
diff --git a/docs/installation/docker.md b/docs/installation/docker.md
index 1ecc7c6ee..2066f83d4 100644
--- a/docs/installation/docker.md
+++ b/docs/installation/docker.md
@@ -6,6 +6,8 @@ nav_order: 4
permalink: /docker
---
+{% include deprecation.html %}
+
# Installation using Docker
This section contains documentation how to install Dendrite using Docker
diff --git a/docs/installation/docker/1_docker.md b/docs/installation/docker/1_docker.md
index f33999725..4d082d9c4 100644
--- a/docs/installation/docker/1_docker.md
+++ b/docs/installation/docker/1_docker.md
@@ -7,6 +7,8 @@ nav_order: 1
permalink: /installation/docker/install
---
+{% include deprecation.html %}
+
# Installing Dendrite using Docker Compose
Dendrite provides an [example](https://github.com/matrix-org/dendrite/blob/main/build/docker/docker-compose.yml)
diff --git a/docs/installation/helm.md b/docs/installation/helm.md
index dd20e0261..b9bf3f3c9 100644
--- a/docs/installation/helm.md
+++ b/docs/installation/helm.md
@@ -6,6 +6,8 @@ nav_order: 3
permalink: /helm
---
+{% include deprecation.html %}
+
# Helm
This section contains documentation how to use [Helm](https://helm.sh/) to install Dendrite on a [Kubernetes](https://kubernetes.io/) cluster.
diff --git a/docs/installation/helm/1_helm.md b/docs/installation/helm/1_helm.md
index 00fe4fdca..992b418fd 100644
--- a/docs/installation/helm/1_helm.md
+++ b/docs/installation/helm/1_helm.md
@@ -7,6 +7,8 @@ nav_order: 1
permalink: /installation/helm/install
---
+{% include deprecation.html %}
+
# Installing Dendrite using Helm
To install Dendrite using the Helm chart, you first have to add the repository using the following commands:
diff --git a/docs/installation/manual.md b/docs/installation/manual.md
index 3ab1fd627..f59893543 100644
--- a/docs/installation/manual.md
+++ b/docs/installation/manual.md
@@ -6,6 +6,8 @@ nav_order: 5
permalink: /manual
---
+{% include deprecation.html %}
+
# Manual Installation
This section contains documentation how to manually install Dendrite
diff --git a/docs/installation/manual/1_build.md b/docs/installation/manual/1_build.md
index 73a626882..f54b1ac43 100644
--- a/docs/installation/manual/1_build.md
+++ b/docs/installation/manual/1_build.md
@@ -7,6 +7,8 @@ nav_order: 1
permalink: /installation/manual/build
---
+{% include deprecation.html %}
+
# Build all Dendrite commands
Dendrite has numerous utility commands in addition to the actual server binaries.
diff --git a/docs/installation/manual/2_database.md b/docs/installation/manual/2_database.md
index 1be602c66..e19912750 100644
--- a/docs/installation/manual/2_database.md
+++ b/docs/installation/manual/2_database.md
@@ -7,6 +7,8 @@ grand_parent: Installation
permalink: /installation/manual/database
---
+{% include deprecation.html %}
+
# Preparing database storage
Dendrite uses SQL databases to store data. Depending on the database engine being used, you
diff --git a/docs/installation/manual/3_signingkey.md b/docs/installation/manual/3_signingkey.md
index 91289fd6a..6a62fa5e1 100644
--- a/docs/installation/manual/3_signingkey.md
+++ b/docs/installation/manual/3_signingkey.md
@@ -6,6 +6,8 @@ nav_order: 3
permalink: /installation/manual/signingkeys
---
+{% include deprecation.html %}
+
# Generating signing keys
All Matrix homeservers require a signing private key, which will be used to authenticate
diff --git a/docs/installation/manual/4_configuration.md b/docs/installation/manual/4_configuration.md
index 624cc4155..ea00c6658 100644
--- a/docs/installation/manual/4_configuration.md
+++ b/docs/installation/manual/4_configuration.md
@@ -6,6 +6,8 @@ nav_order: 4
permalink: /installation/manual/configuration
---
+{% include deprecation.html %}
+
# Configuring Dendrite
A YAML configuration file is used to configure Dendrite. A sample configuration file is
diff --git a/docs/installation/manual/5_starting_dendrite.md b/docs/installation/manual/5_starting_dendrite.md
index d13504372..92d598958 100644
--- a/docs/installation/manual/5_starting_dendrite.md
+++ b/docs/installation/manual/5_starting_dendrite.md
@@ -6,6 +6,8 @@ nav_order: 5
permalink: /installation/manual/start
---
+{% include deprecation.html %}
+
# Starting Dendrite
Once you have completed all preparation and installation steps,
diff --git a/docs/other/p2p.md b/docs/other/p2p.md
index 9f104f025..558ceb1c6 100644
--- a/docs/other/p2p.md
+++ b/docs/other/p2p.md
@@ -3,6 +3,8 @@ title: P2P Matrix
nav_exclude: true
---
+{% include deprecation.html %}
+
# P2P Matrix
These are the instructions for setting up P2P Dendrite, current as of May 2020. There's both Go stuff and JS stuff to do to set this up.
diff --git a/docs/other/peeking.md b/docs/other/peeking.md
index c4ae89811..940729f9e 100644
--- a/docs/other/peeking.md
+++ b/docs/other/peeking.md
@@ -2,6 +2,8 @@
nav_exclude: true
---
+{% include deprecation.html %}
+
## Peeking
Local peeking is implemented as per [MSC2753](https://github.com/matrix-org/matrix-doc/pull/2753).