From 8af65d96f4166cb57ff567a4c937f81c8e5a8aeb Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Thu, 22 Mar 2018 16:22:17 +0100
Subject: [PATCH] Document include guard convention

---
 doc/developer-notes.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/doc/developer-notes.md b/doc/developer-notes.md
index 8f06ee4eca..77ab9cccbe 100644
--- a/doc/developer-notes.md
+++ b/doc/developer-notes.md
@@ -514,6 +514,16 @@ namespace {
     source file into account. This allows quoted includes to stand out more when
     the location of the source file actually is relevant.
 
+- Use include guards to avoid the problem of double inclusion. The header file
+  `foo/bar.h` should use the include guard identifier `BITCOIN_FOO_BAR_H`, e.g.
+
+```c++
+#ifndef BITCOIN_FOO_BAR_H
+#define BITCOIN_FOO_BAR_H
+...
+#endif // BITCOIN_FOO_BAR_H
+```
+
 GUI
 -----