diff --git a/HID-lights.md b/HID-lights.md
index 46a6103..e8f91d2 100644
--- a/HID-lights.md
+++ b/HID-lights.md
@@ -2,3 +2,16 @@ This information is for developers and controller makers.
 
 Spice can translate cabinet light output to USB HID output.
 
+## HID specification
+
+The [HID usage spec](https://www.usb.org/sites/default/files/hut1_6.pdf) is maintained by the USB-IF.
+
+For lights, the `LED Page (0x08)` is the most commonly used, but you are not limited to those.
+
+## Sample code
+
+Arduino code in [UltimatePopnController](https://github.com/CrazyRedMachine/UltimatePopnController/blob/master/popnController/POPNHID.cpp)
+
+Arcin code in [arcin-infinitas](https://github.com/kinetic-flow/arcin-infinitas/blob/master/arcin/report_desc.h)
+
+[Beef-board](https://github.com/HWXLR8/beef-board/blob/master/fw/Descriptors.h)
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