From 48228266fd44c5ec9d4ccd3612f955ce00be6276 Mon Sep 17 00:00:00 2001
From: scbedd <45376673+scbedd@users.noreply.github.com>
Date: Fri, 21 Apr 2023 10:51:43 -0700
Subject: [PATCH] add verbage

---
 tools/test-proxy/Azure.Sdk.Tools.TestProxy/README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/test-proxy/Azure.Sdk.Tools.TestProxy/README.md b/tools/test-proxy/Azure.Sdk.Tools.TestProxy/README.md
index 2e3067b10e1..c94ce6dd517 100644
--- a/tools/test-proxy/Azure.Sdk.Tools.TestProxy/README.md
+++ b/tools/test-proxy/Azure.Sdk.Tools.TestProxy/README.md
@@ -481,6 +481,8 @@ Add a more expansive Header sanitizer that uses a target group instead of filter
 }
 ```
 
+> Note: Regex strings are being passed as a member of a JSON object. As visible in the above example, escape characters must be _double escaped_. `\n` -> `\\n`. `\\` -> `\\\\`. Read the "string" description on [json.org](https://json.org) for more detail.
+
 #### A note about where sanitizers apply
 
 Each sanitizer is optionally prefaced with the **specific part** of the request/response pair that it applies to. These prefixes are