diff --git a/Performance.md b/Performance.md
index 29c30a6..4d2da3d 100644
--- a/Performance.md
+++ b/Performance.md
@@ -30,7 +30,7 @@
   - the difference is not usually perceptible by human beings
   - the random load option is also removed to emphasize this
 - non-standard calls like `statx()`/`getdents()`/`getdents64()`
-  - platform-specific
+  - platform-specific, `nnn` is POSIX-compliant
   - man page _Description_ begins with _"These  are not the interfaces you are interested in."_
 - optimize handling 10K+ entries in a dir
   - not a mass use case