diff --git a/proposals/unsafe-evolution.md b/proposals/unsafe-evolution.md
index 8ff74d95e1..c159b43f12 100644
--- a/proposals/unsafe-evolution.md
+++ b/proposals/unsafe-evolution.md
@@ -184,6 +184,43 @@ partial class C2
 
 For properties, `get` and `set/init` members can be independently declared as `unsafe`; marking the entire property as `unsafe` means that both the `get` and `set/init` members are unsafe.
 
+#### Metadata
+
+When an assembly is compiled with the new memory safety rules, it gets marked with `MemorySafetyRulesAttribute` (detailed below), filled in with `15` as the language version. This is a signal to
+any downstream consumers that any members defined in the assembly will be properly attributed with `RequiresUnsafeAttribute` (detailed below) if an `unsafe` context is required to call them.
+Any member in such an assembly that is not marked with `RequiresUnsafeAttribute` does not require an `unsafe` context to be called, regardless of the types in the signature of the member.
+
+When a member is marked as `unsafe`, the compiler will synthesize a `RequiresUnsafeAttribute` application on the member in metadata. When a user-facing member marked as `unsafe` generates
+hidden members, such as an auto-property's backing field or get/set methods, both the user-facing member and any hidden members generated by that user-facing member are all marked as `unsafe`,
+and `RequiresUnsafeAttribute` is applied to all of them.
+
+```cs
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>Indicates the language version of the memory safety rules used when the module was compiled.</summary>
+    [AttributeUsage(AttributeTargets.Module, Inherited = false)]
+    public sealed class MemorySafetyRulesAttribute : Attribute
+    {
+        /// <summary>Initializes a new instance of the <see cref="MemorySafetyRulesAttribute"/> class.</summary>
+        /// <param name="version">The language version of the memory safety rules used when the module was compiled.</param>
+        public MemorySafetyRulesAttribute(int version) => Version = version;
+ 
+        /// <summary>Gets the language version of the memory safety rules used when the module was compiled.</summary>
+        public int Version { get; }
+    }
+
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Delegate | AttributeTargets.Constructor, AllowMultiple = false, Inherited = true)]
+    public sealed class RequiresUnsafeAttribute : Attribute
+    {
+    }
+}
+```
+
+#### Compat mode
+
+For compat purposes, and to reduce the number of false negatives that occur when enabling the new rules, we have a fallback rule for modules that have not been updated to the new rules. For such modules,
+a member is considered `unsafe` if it has a pointer or function pointer type in its signature.
+
 ## Open questions
 
 ### Local functions/lambda safe contexts