diff --git a/README.md b/README.md
index 92b43ae..6c1472a 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # ckit
 
-A minimal collection of reusable C headers for >=C89.
+A minimal collection of reusable C headers for ≥C89.
 
 ## Available Headers
 
diff --git a/arena.h b/arena.h
index 9d6c996..af178ab 100644
--- a/arena.h
+++ b/arena.h
@@ -3,6 +3,10 @@
  * arena.h - Minimal, Portable Freestanding Arena Allocator
  * ============================================================================
  *
+ * Supported C standards:
+ *     arena.h aims to support anything from ANSI C to C23, though ANSI C support
+ *     may be broken.
+ *
  * Overview:
  *     This header provides a simple, drop-in arena allocator suitable for
  *     freestanding or embedded environments where standard malloc/free may not