diff --git a/man5/proc.5 b/man5/proc.5
index 2a9154af2..9d5eff9bd 100644
--- a/man5/proc.5
+++ b/man5/proc.5
@@ -2018,7 +2018,7 @@ encoded using the following two-letter codes:
     ac  - area is accountable
     nr  - swap space is not reserved for the area
     ht  - area uses huge tlb pages
-    nl  - non-linear mapping
+    nl  - non-linear mapping (removed in Linux 4.0)
     ar  - architecture specific flag
     wf  - wipe on fork (since Linux 4.14)
     dd  - do not include area into core dump