diff --git a/doc/writing-a-new-driver.md b/doc/writing-a-new-driver.md
index 950970e4b..aaa9cbe53 100644
--- a/doc/writing-a-new-driver.md
+++ b/doc/writing-a-new-driver.md
@@ -11,3 +11,10 @@ features you want.
 The first components you will be interacting with is @ref st_prober find the
 hardware devices and setup a working system, along with the @ref aux code that
 provides various helpers. You can look at other @ref drv on how to start.
+
+## Probing
+
+When should I implement the @ref xrt_auto_prober interface? The answer is not
+too hard: you use the auto prober interface when the basic USB VID/PID-based
+interface is not sufficient for you to detect presence/absence of your device,
+or if you don't want to use the built-in HID support for some reason.