diff --git a/SECURITY.md b/SECURITY.md
index 54a38a5..989d516 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -54,6 +54,27 @@ remedy for those is to upgrade.
 | 6.2.x | ✅ |
 | < 6.2 | ❌ |
 
+### For how long
+
+There is no fixed end-of-support date. The current line targets **.NET 10** (`net10.0`, and EF Core
+10 for the EF Core packages), and the intention is to keep it maintained for as long as Microsoft
+supports that .NET release (.NET 10 is LTS, supported until November 2028), or until a new major of
+this package supersedes it, whichever comes first — majors here are cheap, and a new one has never
+meant the old one lost fixes before its successor shipped. If that intention changes, it is recorded
+here before anywhere else.
+
+### If this project stops being maintained
+
+This is a single-maintainer project, and that is the honest continuity risk. The signal would be
+unambiguous: the repository archived, the packages marked deprecated on nuget.org, and a note here.
+Published versions stay on nuget.org regardless (a package can be unlisted, not removed), the code
+is MIT-licensed, and the release path needs nothing but this repository — forking is the intended
+continuity mechanism, not a fallback.
+
+Advisories are published as GitHub Security Advisories, which reach the GitHub Advisory Database
+and from there `dotnet restore` (NuGetAudit): a consumer on an affected version sees a build
+warning without subscribing to anything.
+
 ## Where this package sits
 
 Useful context for judging impact, and for anyone doing supply-chain due diligence.
diff --git a/test/CodoMetis.ValueRanges.Conventions.Tests/SecurityPolicyConventionTests.cs b/test/CodoMetis.ValueRanges.Conventions.Tests/SecurityPolicyConventionTests.cs
index 4507445..d603472 100644
--- a/test/CodoMetis.ValueRanges.Conventions.Tests/SecurityPolicyConventionTests.cs
+++ b/test/CodoMetis.ValueRanges.Conventions.Tests/SecurityPolicyConventionTests.cs
@@ -22,12 +22,45 @@ public sealed class SecurityPolicyConventionTests
     private static readonly Regex UnsupportedRow =
         new(@"^\|\s*<\s*(?<major>\d+)\.(?<minor>\d+)\s*\|\s*❌\s*\|", RegexOptions.Multiline);
 
+    /// <summary>"the current line targets **.NET 10**" — the number the horizon statement is anchored to.</summary>
+    private static readonly Regex TargetsDotNet =
+        new(@"targets \*\*\.NET (?<major>\d+)\*\*", RegexOptions.None);
+
     [TestMethod]
     public void SecurityPolicy_Exists()
     {
         Assert.IsTrue(SecurityPolicy.Exists, $"No SECURITY.md at the repository root ({SecurityPolicy.FullName}).");
     }
 
+    /// <summary>
+    /// The support horizon is phrased against the .NET major the packages target, and that number
+    /// lives in the core project's TargetFramework. When the TFM moves to net11.0 the sentence has
+    /// to move with it, or the policy promises support against a release the package no longer
+    /// targets.
+    /// </summary>
+    [TestMethod]
+    public void TheSupportHorizon_NamesTheTargetedDotNetMajor()
+    {
+        var text  = File.ReadAllText(SecurityPolicy.FullName);
+        var match = TargetsDotNet.Match(text);
+
+        Assert.IsTrue(
+            match.Success,
+            "SECURITY.md has no 'targets **.NET N**' sentence in its support horizon — a consumer doing "
+          + "due diligence needs to know which platform line the support intention is tied to.");
+
+        var core = RepoLayout.PackableProjects.Single(project => project.PackageId == "CodoMetis.ValueRanges");
+        var tfm  = core.Property("TargetFramework") ?? "";
+        var tfmMajor = Regex.Match(tfm, @"^net(?<major>\d+)\.").Groups["major"].Value;
+
+        Assert.IsFalse(string.IsNullOrEmpty(tfmMajor), $"Could not read a net<major>.<minor> TargetFramework from {core.File.Name} (got '{tfm}').");
+
+        Assert.AreEqual(
+            tfmMajor, match.Groups["major"].Value,
+            $"SECURITY.md says the current line targets .NET {match.Groups["major"].Value}, but "
+          + $"{core.File.Name} targets {tfm}. Move the horizon statement with the TargetFramework.");
+    }
+
     [TestMethod]
     public void TheSupportedVersionsTable_NamesTheShippedMinor()
     {