Add /// comments

src/libraries/System.Private.Uri/src/System/Uri.cs

@@ -121,6 +121,9 @@ internal enum Flags : ulong
             IriCanonical = 0x78000000000,
             UnixPath = 0x100000000000,
 
+            /// <summary>
+            /// Disables any validation/normalization past the authority. Fragments will always be empty. GetComponents will throw for Path/Query.
+            /// </summary>
             DisablePathAndQueryCanonicalization = 0x200000000000,
 
             /// <summary>
@@ -414,6 +417,11 @@ public Uri(string uriString, UriKind uriKind)
             DebugSetLeftCtor();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Uri"/> class with the specified URI and additional <see cref="UriCreationOptions"/>.
+        /// </summary>
+        /// <param name="uriString">A string that identifies the resource to be represented by the <see cref="Uri"/> instance.</param>
+        /// <param name="creationOptions">Options that control how the <seealso cref="Uri"/> is created and behaves.</param>
         public Uri(string uriString, in UriCreationOptions creationOptions)
         {
             if (uriString is null)

src/libraries/System.Private.Uri/src/System/UriCreationOptions.cs

@@ -3,8 +3,26 @@
 
 namespace System
 {
+    /// <summary>
+    /// Options that control how a <seealso cref="Uri"/> is created and behaves.
+    /// </summary>
     public struct UriCreationOptions
     {
-        public bool DangerousDisablePathAndQueryCanonicalization { readonly get; set; }
+        private bool _disablePathAndQueryCanonicalization;
+
+        /// <summary>
+        /// Disables validation and normalization of the Path and Query.
+        /// No transformations of the URI past the Authority will take place.
+        /// <see cref="Uri"/> instances created with this option do not support <see cref="Uri.Fragment"/>s.
+        /// <see cref="Uri.GetComponents(UriComponents, UriFormat)"/> may not be used for <see cref="UriComponents.Path"/> or <see cref="UriComponents.Query"/>.
+        /// Be aware that disabling canonicalization also means that reserved characters will not be escaped,
+        /// which may corrupt the HTTP request and makes the application subject to request smuggling.
+        /// Only set this option if you have ensured that the URI string is already sanitized.
+        /// </summary>
+        public bool DangerousDisablePathAndQueryCanonicalization
+        {
+            readonly get => _disablePathAndQueryCanonicalization;
+            set => _disablePathAndQueryCanonicalization = value;
+        }
     }
 }

src/libraries/System.Private.Uri/src/System/UriExt.cs

@@ -262,6 +262,13 @@ public static bool TryCreate([NotNullWhen(true)] string? uriString, UriKind uriK
             return e is null && result != null;
         }
 
+        /// <summary>
+        /// Creates a new <see cref="Uri"/> using the specified <see cref="string"/> instance and <see cref="UriCreationOptions"/>.
+        /// </summary>
+        /// <param name="uriString">The string representation of the <see cref="Uri"/>.</param>
+        /// <param name="creationOptions">Options that control how the <seealso cref="Uri"/> is created and behaves.</param>
+        /// <param name="result">The constructed <see cref="Uri"/>.</param>
+        /// <returns><see langword="true"/> if the <see cref="Uri"/> was successfully created; otherwise, <see langword="false"/>.</returns>
         public static bool TryCreate([NotNullWhen(true)] string? uriString, in UriCreationOptions creationOptions, [NotNullWhen(true)] out Uri? result)
         {
             if (uriString is null)