diff --git a/README.md b/README.md
index 613e1ae..7d52b2c 100644
--- a/README.md
+++ b/README.md
@@ -60,6 +60,8 @@ Example: [pkg/de-p1st-gnupg/PKGBUILD](pkg/de-p1st-gnupg/PKGBUILD)
 * systemd.preset - Service enablement presets
 * [man 5 systemd.preset](https://www.systutorials.com/docs/linux/man/5-systemd.preset/)
 
+**Note**: the preset name shall start with a two digit number.
+
 ```shell
 install -Dm0644 systemd.preset "$pkgdir"/usr/lib/systemd/system-preset/20-"$pkgname".preset
 ```