diff --git a/README.md b/README.md
index 5f8a7ae..54c6a6b 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,9 @@ How to use
 ---
 To use the guix-glicid channel, add these lines to ~/.config/guix/channels.scm or /etc/guix/channels.scm :
 
-For stable release :
+<details>
+  <summary>For stable release :</summary>
+
 ```
 (channel
     (name 'glicid)
@@ -20,10 +22,34 @@ For stable release :
     (branch "main"))
 ```
 
-For devel release :
+</details>
+
+<details>
+  <summary>For devel release :</summary>
+
 ```
 (channel
     (name 'glicid)
     (url "https://gitlab.univ-nantes.fr/glicid-public/guix-glicid.git")
     (branch "devel"))
 ```
+
+</details>
+
+Substitutes configuration
+---
+
+We offer substitutes (pre-built binaries) for these channels.
+
+<details>
+  <summary>Substitutes configuration :</summary>
+
+To obtain substitutes for packages in theses channel, add https://guix-substitutes.glicid.fr/ and authorize this key:
+```
+(public-key 
+  (ecc 
+    (curve Ed25519)
+    (q #C07EE66C971860BFE963856ADD29F5F97E347C0C97E4A915B0BE74114EB443AB#)))
+```
+
+</details>