diff --git a/Sources/Foundation/NSError.swift b/Sources/Foundation/NSError.swift
index 9543fb0c56..5d9d78672f 100644
--- a/Sources/Foundation/NSError.swift
+++ b/Sources/Foundation/NSError.swift
@@ -803,6 +803,7 @@ extension URLError {
     }
 
     /// The string for the URL which caused a load to fail.
+    @available(swift, deprecated: 6.1, message: "Use failingURL instead")
     public var failureURLString: String? {
         return _nsUserInfo[NSURLErrorFailingURLStringErrorKey] as? String
     }
diff --git a/Sources/Foundation/NSURLError.swift b/Sources/Foundation/NSURLError.swift
index a2fbb62b60..a3133962e1 100644
--- a/Sources/Foundation/NSURLError.swift
+++ b/Sources/Foundation/NSURLError.swift
@@ -20,6 +20,7 @@ public let NSURLErrorFailingURLErrorKey: String = "NSErrorFailingURLKey"
 
 /// The `NSError` userInfo dictionary key used to store and retrieve the NSString
 /// object for the URL which caused a load to fail.
+@available(swift, deprecated: 6.1, message: "Use NSURLErrorFailingURLErrorKey instead")
 public let NSURLErrorFailingURLStringErrorKey: String = "NSErrorFailingURLStringKey"
 
 /// The `NSError` userInfo dictionary key used to store and retrieve the
diff --git a/Sources/FoundationNetworking/NSURLRequest.swift b/Sources/FoundationNetworking/NSURLRequest.swift
index cdda7bcadd..a0d179863c 100644
--- a/Sources/FoundationNetworking/NSURLRequest.swift
+++ b/Sources/FoundationNetworking/NSURLRequest.swift
@@ -373,6 +373,7 @@ open class NSURLRequest : NSObject, NSSecureCoding, NSCopying, NSMutableCopying
     
     open internal(set) var httpShouldHandleCookies: Bool = true
     
+    @available(swift, deprecated: 6.1, message: "HTTP/1 pipelining has known compatibility issues, please adopt HTTP/2 and HTTP/3 instead")
     open internal(set) var httpShouldUsePipelining: Bool = true
 
     open override var description: String {
@@ -573,6 +574,7 @@ open class NSMutableURLRequest : NSURLRequest {
         set { super.httpShouldHandleCookies = newValue }
     }
     
+    @available(swift, deprecated: 6.1, message: "HTTP/1 pipelining has known compatibility issues, please adopt HTTP/2 and HTTP/3 instead")
     open override var httpShouldUsePipelining: Bool {
         get { return super.httpShouldUsePipelining }
         set { super.httpShouldUsePipelining = newValue }
diff --git a/Sources/FoundationNetworking/URLProtectionSpace.swift b/Sources/FoundationNetworking/URLProtectionSpace.swift
index 6470657bc5..26dcc234cf 100644
--- a/Sources/FoundationNetworking/URLProtectionSpace.swift
+++ b/Sources/FoundationNetworking/URLProtectionSpace.swift
@@ -29,6 +29,7 @@ public let NSURLProtectionSpaceHTTPS: String = "NSURLProtectionSpaceHTTPS"
    @const NSURLProtectionSpaceFTP
    @abstract The protocol for FTP
 */
+@available(swift, deprecated: 6.1, message: "FTP is deprecated")
 public let NSURLProtectionSpaceFTP: String = "NSURLProtectionSpaceFTP"
 
 /*!
@@ -47,6 +48,7 @@ public let NSURLProtectionSpaceHTTPSProxy: String = "NSURLProtectionSpaceHTTPSPr
     @const NSURLProtectionSpaceFTPProxy
     @abstract The proxy type for ftp proxies
 */
+@available(swift, deprecated: 6.1, message: "FTP is deprecated")
 public let NSURLProtectionSpaceFTPProxy: String = "NSURLProtectionSpaceFTPProxy"
 
 /*!
diff --git a/Sources/FoundationNetworking/URLRequest.swift b/Sources/FoundationNetworking/URLRequest.swift
index f8ab4c8c7d..e87201e528 100644
--- a/Sources/FoundationNetworking/URLRequest.swift
+++ b/Sources/FoundationNetworking/URLRequest.swift
@@ -224,6 +224,7 @@ public struct URLRequest : ReferenceConvertible, Equatable, Hashable, Sendable {
     /// `true` if the receiver should transmit before the previous response
     /// is received.  `false` if the receiver should wait for the previous response
     /// before transmitting.
+    @available(swift, deprecated: 6.1, message: "HTTP/1 pipelining has known compatibility issues, please adopt HTTP/2 and HTTP/3 instead")
     public var httpShouldUsePipelining: Bool {
         get {
             return _handle.map { $0.httpShouldUsePipelining }
diff --git a/Sources/FoundationNetworking/URLSession/URLSessionConfiguration.swift b/Sources/FoundationNetworking/URLSession/URLSessionConfiguration.swift
index 9236854f4c..89bb774dd7 100644
--- a/Sources/FoundationNetworking/URLSession/URLSessionConfiguration.swift
+++ b/Sources/FoundationNetworking/URLSession/URLSessionConfiguration.swift
@@ -204,6 +204,7 @@ open class URLSessionConfiguration : NSObject, NSCopying, @unchecked Sendable {
      */
     
     /* Allow the use of HTTP pipelining */
+    @available(swift, deprecated: 6.1, message: "HTTP/1 pipelining has known compatibility issues, please adopt HTTP/2 and HTTP/3 instead")
     open var httpShouldUsePipelining: Bool
     
     /* Allow the session to set cookies on requests */
@@ -229,9 +230,7 @@ open class URLSessionConfiguration : NSObject, NSCopying, @unchecked Sendable {
     /* The URL resource cache, or nil to indicate that no caching is to be performed */
     open var urlCache: URLCache?
     
-    /* Enable extended background idle mode for any tcp sockets created.    Enabling this mode asks the system to keep the socket open
-     *  and delay reclaiming it when the process moves to the background (see https://developer.apple.com/library/ios/technotes/tn2277/_index.html)
-     */
+    @available(swift, deprecated: 6.1, message: "Not supported")
     open var shouldUseExtendedBackgroundIdleMode: Bool
     
     /* An optional array of Class objects which subclass URLProtocol.
@@ -253,6 +252,10 @@ open class URLSessionConfiguration : NSObject, NSCopying, @unchecked Sendable {
      @available(*, unavailable, message: "Not available on non-Darwin platforms")
      open var multipathServiceType: URLSessionConfiguration.MultipathServiceType { NSUnsupported() }
 
+    /* Uses the classic network loader */
+    @available(*, unavailable, message: "Not available on non-Darwin platforms")
+    open var usesClassicLoadingMode: Bool { NSUnsupported() }
+
 }
 
 @available(*, unavailable, message: "Not available on non-Darwin platforms")
diff --git a/Sources/FoundationNetworking/URLSession/URLSessionTaskMetrics.swift b/Sources/FoundationNetworking/URLSession/URLSessionTaskMetrics.swift
index 5de19fdeef..eaa0cdd030 100644
--- a/Sources/FoundationNetworking/URLSession/URLSessionTaskMetrics.swift
+++ b/Sources/FoundationNetworking/URLSession/URLSessionTaskMetrics.swift
@@ -29,6 +29,7 @@ open class URLSessionTaskMetrics : NSObject, @unchecked Sendable {
     public enum ResourceFetchType: Int, Sendable {
         case unknown = 0
         case networkLoad = 1
+        @available(swift, deprecated: 6.1, message: "Server push is not supported")
         case serverPush = 2
         case localCache = 3
     }