3 files changed, 55 insertions, 0 deletions
diff --git a/docs/en/admins/01_Index.md b/docs/en/admins/01_Index.md
index 9f36f3949..749d44af3 100644
--- a/docs/en/admins/01_Index.md
+++ b/docs/en/admins/01_Index.md
@@ -10,6 +10,7 @@ Learn how to install, update, and backup FreshRSS, as well as how to use the com
 
 * [User management](12_User_management.md)
 * [Backing up FreshRSS](05_Backup.md)
+* [Installing and managing extensions](15_extensions.md)
 * [Installing themes](11_Themes.md)
 * [Installation on Debian 9/Ubuntu 16.04](06_LinuxInstall.md)
 * [Installation on Cloud Providers](14_CloudProviders.md)
diff --git a/docs/en/admins/15_extensions.md b/docs/en/admins/15_extensions.md
new file mode 100644
index 000000000..5fc023b7c
--- /dev/null
+++ b/docs/en/admins/15_extensions.md
@@ -0,0 +1,53 @@
+# Extensions
+
+Not every feature is relevant for all users, but some special features are relevant to the right person. That is why FreshRSS is extendable.
+
+There are some "official" extensions (supported and published by the FreshRSS development team and community) and "community" extensions (developed and published individually by third-party developers).
+
+## Extension repositories
+
+Most known extensions are listed in the front end: see configuration menu `Configuration/Extensions`.
+
+## How to install
+
+Upload the folder (f.e. `CustomCSS`) of your chosen extension into your `./extensions` directory.
+
+Result: Content of `./extensions/CustomCSS/` has f.e. `extension.php`, `metadata.json`, `configure.php`, `README.md` files and the folders `i18n` and `static`
+
+Important: Do not delete or overwrite the existing files `./extensions/.gitignore` and `./extensions/README.md`.
+
+## How to enable/disable and manage
+
+See in the front end: configuration menu `Configuration/Extensions`
+
+### User extensions
+
+Every user has to manage the extensions by themselves. Configuration via the gear icon is valid only for that user, not for other users.
+
+metadata.json:
+
+```json
+{
+  "type": "user"
+}
+```
+
+### System extensions
+
+Only administrators can enable/disable system extensions. The configuration via the gear icon is valid for every user.
+
+metadata.json:
+
+```json
+{
+  "type": "system"
+}
+```
+
+### pre installed extensions (core extensions)
+
+See folder: `.lib/core-extensions`
+
+Two system extensions are already pre-installed: `Google-Groups` and `Tumblr-GDPR`.
+
+Important: do not install your chosen extensions here!
diff --git a/docs/en/index.md b/docs/en/index.md
index 917f46c2e..d529f2f12 100644
--- a/docs/en/index.md
+++ b/docs/en/index.md
@@ -14,6 +14,7 @@ FreshRSS has a lot of features including:
 * Statistics to show you the publishing frequency all the websites you follow
 * Import/export of your feeds into OPML format
 * Several themes created by the community
+* Several extensions created by the community
 * "Google Reader"-like API to connect Android applications
 * The application is "responsive," which means it adapts to small screens so you can bring articles in your pocket
 * Self-hosted: the code is free (under AGPL3 licence), so you can host your own instance of FreshRSS