diff --git a/docs/architecture/README.md b/docs/architecture/README.md
index 3c00cb9..d50bd62 100644
--- a/docs/architecture/README.md
+++ b/docs/architecture/README.md
@@ -87,6 +87,7 @@ Read in this order if you are new:
 | [syscalls.md](syscalls.md) | The one table everything is generated from, and how a musl binary runs unmodified. |
 | [filesystem.md](filesystem.md) | The VFS, the buffer cache, mounts, procfs. |
 | [schfs.md](schfs.md) | The copy-on-write root filesystem. |
+| [fat.md](fat.md) | FAT12/16/32 with long names: USB sticks, SD cards, the ESP. |
 | [devices.md](devices.md) | Buses, classes, binding, and the vtables consumers talk to. |
 | [usb.md](usb.md) | xHCI, the USB core, and the three class drivers. |
 | [graphics.md](graphics.md) | Framebuffer, text rendering, the console, and PSOGM. |