Reword some regex safety warnings

xml/System.Text.RegularExpressions/Regex.xml

@@ -68,12 +68,16 @@
             allow use of regular expressions without instantiating a Regex explicitly.
             </summary>
     <remarks>
-      <para>
-            The <see cref="T:System.Text.RegularExpressions.Regex" /> class represents the .NET regular expression engine.
-            It can be used to quickly parse large amounts of text to find specific character patterns;
-            to extract, edit, replace, or delete text substrings; and to add the extracted strings to a
-            collection to generate a report.
-            </para>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+ The `Regex` class represents the .NET regular expression engine. It can be used to quickly parse large amounts of text to find specific character patterns; to extract, edit, replace, or delete text substrings; and to add the extracted strings to a collection to generate a report.
+
+> [!WARNING]
+> Unrestricted use of this class with untrusted input can subject applications to [denial-of-service attacks](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS). Consult [Best practices for regular expressions in .NET](/dotnet/standard/base-types/best-practices-regex) for guidance on how to safely use this class with untrusted input.
+
+ ]]></format>
     </remarks>
     <threadsafe>The <see cref="T:System.Text.RegularExpressions.Regex" /> class is immutable (read-only) and thread safe. <see cref="T:System.Text.RegularExpressions.Regex" /> objects can be created on any thread and shared between threads. For more information, see <see href="/dotnet/standard/base-types/thread-safety-in-regular-expressions">Thread Safety</see>.</threadsafe>
     <altmember cref="T:System.Configuration.RegexStringValidator" />
@@ -199,9 +203,6 @@
 
 ## Remarks
 
-> [!WARNING]
-> When using <xref:System.Text.RegularExpressions> to process untrusted input, pass a [time-out value](/dotnet/standard/base-types/best-practices-regex#use-time-out-values) to prevent malicious users from causing a [denial-of-service attack](https://www.cisa.gov/news-events/news/understanding-denial-service-attacks). A time-out value specifies how long a pattern-matching method should try to find a match before it times out.
-
  The `pattern` parameter consists of regular expression language elements that symbolically describe the string to match. For more information about regular expressions, see the [.NET Regular Expressions](/dotnet/standard/base-types/regular-expressions) and [Regular Expression Language - Quick Reference](/dotnet/standard/base-types/regular-expression-language-quick-reference) topics.
 
  Calling the <xref:System.Text.RegularExpressions.Regex.%23ctor(System.String)> constructor is equivalent to calling the <xref:System.Text.RegularExpressions.Regex.%23ctor(System.String,System.Text.RegularExpressions.RegexOptions)> constructor with a value of <xref:System.Text.RegularExpressions.RegexOptions.None> for the `options` argument.
@@ -347,9 +348,6 @@
 
 ## Remarks
 
-> [!WARNING]
-> When using <xref:System.Text.RegularExpressions> to process untrusted input, pass a [time-out value](/dotnet/standard/base-types/best-practices-regex#use-time-out-values) to prevent malicious users from causing a [denial-of-service attack](https://www.cisa.gov/news-events/news/understanding-denial-service-attacks). A time-out value specifies how long a pattern-matching method should try to find a match before it times out.
-
  The `pattern` parameter consists of regular expression language elements that symbolically describe the string to match. For more information about regular expressions, see the [.NET Regular Expressions](/dotnet/standard/base-types/regular-expressions) and [Regular Expression Language - Quick Reference](/dotnet/standard/base-types/regular-expression-language-quick-reference) topics.
 
  A <xref:System.Text.RegularExpressions.Regex> object is immutable, which means that it can be used only for the match parameters you define when you create it. However, it can be used any number of times without being recompiled.

xml/System.Text.RegularExpressions/RegexOptions.xml

@@ -479,7 +479,7 @@
       <Docs>
         <summary>
             Enable matching using an approach that avoids backtracking and guarantees linear-time processing
-            in the length of the input. For more information, see the
+            in the length of the input. For more information, see the "Non-Backtracking mode" section in the
             <see href="https://learn.microsoft.com/dotnet/standard/base-types/regular-expression-options">
             Regular Expression Options</see> article.
             </summary>