From 1cafa1fd7ec8253c9490c2fa1edf51d6a70d47b9 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 10 Aug 2025 14:08:04 +0200
Subject: [PATCH] modules/README: init

Explain the purpose and usage of this new directory.
---
 modules/README.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 modules/README.md

diff --git a/modules/README.md b/modules/README.md
new file mode 100644
index 000000000000..777ab9839949
--- /dev/null
+++ b/modules/README.md
@@ -0,0 +1,9 @@
+# `<nixpkgs>/modules`
+
+This directory hosts subdirectories representing each module [class](https://nixos.org/manual/nixpkgs/stable/#module-system-lib-evalModules-param-class) for which the `nixpkgs` repository has user-importable modules.
+
+Exceptions:
+- `_class = "nixos";` modules go in the `<nixpkgs>/nixos/modules` tree
+- modules whose only purpose is to test code in this repository
+
+The emphasis is on _importable_ modules, i.e. ones that aren't inherent to and built into the Module System application.