From 5138f21df75026c24ee327b1fc043a16c5231ecf Mon Sep 17 00:00:00 2001
From: sburman <sburman@twilio.com>
Date: Fri, 24 Nov 2023 23:47:17 +0530
Subject: [PATCH] comments

---
 USE_CASES.md                          | 24 ++++++++++++++++++++++++
 src/SendGrid/SendGridClientOptions.cs |  3 +++
 2 files changed, 27 insertions(+)

diff --git a/USE_CASES.md b/USE_CASES.md
index 63dd80c84..271374842 100644
--- a/USE_CASES.md
+++ b/USE_CASES.md
@@ -920,6 +920,30 @@ var client = new SendGridClient(options);
 
 ```
 
+The SendGridClientOptions object can also be used to set the region to "eu", which will send the 
+request to https://api.eu.sendgrid.com/. By default it is set to https://api.sendgrid.com/, e.g.
+
+```csharp
+
+var options = new SendGridClientOptions
+{
+    ApiKey = Environment.GetEnvironmentVariable("NAME_OF_THE_ENVIRONMENT_VARIABLE_FOR_YOUR_SENDGRID_KEY"),
+    ReliabilitySettings = new ReliabilitySettings(2, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(3)),
+    Host = "Your-Host",
+    UrlPath = "Url-Path",
+    Version = "3",
+    RequestHeaders = new Dictionary<string, string>() {{"header-key", "header-value"}}
+};
+options.SetDataResidency("eu");
+var client = new SendGridClient(options);
+
+OR
+
+options.SetDataResidency("global");
+var client = new SendGridClient(options);
+
+```
+
 <a name="domain-authentication"></a>
 # How to Setup a Domain Authentication
 
diff --git a/src/SendGrid/SendGridClientOptions.cs b/src/SendGrid/SendGridClientOptions.cs
index 3cfb2986f..f46d7c9d0 100644
--- a/src/SendGrid/SendGridClientOptions.cs
+++ b/src/SendGrid/SendGridClientOptions.cs
@@ -48,6 +48,9 @@ public string ApiKey
         /// Sets the data residency for the SendGrid client.
         /// </summary>
         /// <param name="region">The desired data residency region ("global" or "eu").</param>
+        /// Global is the default residency (or region)
+        /// Global region means the message will be sent through https://api.sendgrid.com
+        /// EU region means the message will be sent through https://api.eu.sendgrid.com
         /// <returns>The updated SendGridClientOptions instance.</returns>
         public SendGridClientOptions SetDataResidency(string region)
         {