make guidance more clear (#36687)

Author: gewarren

docs/fundamentals/networking/http/httpclient-guidelines.md

@@ -3,7 +3,7 @@ title: HttpClient guidelines for .NET
 description: Learn about using HttpClient instances to send HTTP requests and how you can manage clients using IHttpClientFactory in your .NET apps.
 author: gewarren
 ms.author: gewarren
-ms.date: 08/31/2022
+ms.date: 08/14/2023
 ---
 
 # Guidelines for using HttpClient
@@ -26,30 +26,31 @@ The preceding `HttpClient` is configured to reuse connections for 15 minutes. Af
 
 ## Pooled connections
 
-The connection pool for an <xref:System.Net.Http.HttpClient> is linked to the underlying <xref:System.Net.Http.SocketsHttpHandler>. When the <xref:System.Net.Http.HttpClient> instance is disposed, it disposes all existing connections inside the pool. If you later send a request to the same server, a new connection must be recreated. As a result, there's a performance penalty for unnecessary connection creation. Moreover, TCP ports are not released immediately after connection closure, see TCP `TIME-WAIT` in [RFC 9293](https://www.rfc-editor.org/rfc/rfc9293.html#section-3.3.2). So if the rate of requests is high, the operating system limit of available ports might be exhausted. To avoid port exhaustion problems, reusing <xref:System.Net.Http.HttpClient> instance for as many HTTP requests as possible is recommended. This can be achieved by following [the recommended usage](#recommended-use).
+The connection pool for an <xref:System.Net.Http.HttpClient> is linked to the underlying <xref:System.Net.Http.SocketsHttpHandler>. When the <xref:System.Net.Http.HttpClient> instance is disposed, it disposes all existing connections inside the pool. If you later send a request to the same server, a new connection must be recreated. As a result, there's a performance penalty for unnecessary connection creation. Moreover, TCP ports are not released immediately after connection closure. (For more information on that, see TCP `TIME-WAIT` in [RFC 9293](https://www.rfc-editor.org/rfc/rfc9293.html#section-3.3.2).) If the rate of requests is high, the operating system limit of available ports might be exhausted. To avoid port exhaustion problems, we [recommend](#recommended-use) reusing <xref:System.Net.Http.HttpClient> instances for as many HTTP requests as possible.
 
 ## Recommended use
 
+To summarize recommended `HttpClient` use in terms of lifetime management, you should use either *long-lived* clients and set `PooledConnectionLifetime` (.NET Core and .NET 5+) or *short-lived* clients created by `IHttpClientFactory`.
+
 - In .NET Core and .NET 5+:
-  - Use a `static` or *singleton* <xref:System.Net.Http.HttpClient> instance with <xref:System.Net.Http.SocketsHttpHandler.PooledConnectionLifetime> set to the desired interval, such as two minutes, depending on expected DNS changes. This solves both the port exhaustion and DNS changes problems without adding the overhead of <xref:System.Net.Http.IHttpClientFactory>. If you need to be able to mock your handler, you can register it separately.
+
+  - Use a `static` or *singleton* <xref:System.Net.Http.HttpClient> instance with <xref:System.Net.Http.SocketsHttpHandler.PooledConnectionLifetime> set to the desired interval, such as 2 minutes, depending on expected DNS changes. This solves both the port exhaustion and DNS changes problems without adding the overhead of <xref:System.Net.Http.IHttpClientFactory>. If you need to be able to mock your handler, you can register it separately.
+
   > [!TIP]
-  > Any reasonably limited number of <xref:System.Net.Http.HttpClient> instances will work as well. What matters here is that they are not created and disposed with each request as they each contain a connection pool. Using more than one instance is necessary for scenarios with multiple proxies or to separate cookie containers without completely disabling cookie handling.
+  > If you only use a limited number of <xref:System.Net.Http.HttpClient> instances, that's also an acceptable strategy. What matters is that they're not created and disposed with each request, as they each contain a connection pool. Using more than one instance is necessary for scenarios with multiple proxies or to separate cookie containers without completely disabling cookie handling.
 
   - Using <xref:System.Net.Http.IHttpClientFactory>, you can have multiple, differently configured clients for different use cases. However, be aware that the factory-created clients are intended to be short-lived, and once the client is created, the factory no longer has control over it.
 
     The factory pools <xref:System.Net.Http.HttpMessageHandler> instances, and, if its lifetime hasn't expired, a handler can be reused from the pool when the factory creates a new <xref:System.Net.Http.HttpClient> instance. This reuse avoids any socket exhaustion issues.
 
     If you desire the configurability that <xref:System.Net.Http.IHttpClientFactory> provides, we recommend using the [typed-client approach](../../../core/extensions/httpclient-factory.md#typed-clients).
-- In .NET Framework, use <xref:System.Net.Http.IHttpClientFactory> to manage your `HttpClient` instances. If you create a new client instance for each request, you can exhaust available sockets.
+
+- In .NET Framework, use <xref:System.Net.Http.IHttpClientFactory> to manage your `HttpClient` instances. If you don't use the factory and instead create a new client instance for each request yourself, you can exhaust available ports.
 
     > [!TIP]
     > If your app requires cookies, consider disabling automatic cookie handling or avoiding <xref:System.Net.Http.IHttpClientFactory>. Pooling the <xref:System.Net.Http.HttpMessageHandler> instances results in sharing of <xref:System.Net.CookieContainer> objects. Unanticipated <xref:System.Net.CookieContainer> object sharing often results in incorrect code.
 
-### HttpClient lifetime management
-
-To summarize recommended `HttpClient` use in terms of lifetime management, you should use either **long-lived** clients with `PooledConnectionLifetime` set up (.NET Core and .NET 5+) or **short-lived** clients created by `IHttpClientFactory`.
-
-To learn more about managing `HttpClient` lifetime with `IHttpClientFactory`, see [`IHttpClientFactory` guidelines](../../../core/extensions/httpclient-factory.md#httpclient-lifetime-management).
+For more information about managing `HttpClient` lifetime with `IHttpClientFactory`, see [`IHttpClientFactory` guidelines](../../../core/extensions/httpclient-factory.md#httpclient-lifetime-management).
 
 ## See also