diff --git a/DOCUMENTATION.md b/DOCUMENTATION.md
index 28aec97..fbd2112 100644
--- a/DOCUMENTATION.md
+++ b/DOCUMENTATION.md
@@ -62,6 +62,11 @@
 
 ## Special variables
 
+- `FLSYM_LEFT_PRE` / `FLSYM_LEFT_POST`
+  - Description: customizable symbols used as prefix and suffix for left segments
+- `FLSYM_RIGHT_PRE` / `FLSYM_RIGHT_POST`
+  - Description: customizable symbols used as prefix and suffix for right segments
+
 - `FLINE_DEFAULT_PROMPT`
   - Possible values: list of segment
   - Used by: `fishline`