diff --git a/Projects/Server.Tests/Tests/PropertyList/ObjectPropertyListSpanAddTests.cs b/Projects/Server.Tests/Tests/PropertyList/ObjectPropertyListSpanAddTests.cs
new file mode 100644
index 000000000..7972739e1
--- /dev/null
+++ b/Projects/Server.Tests/Tests/PropertyList/ObjectPropertyListSpanAddTests.cs
@@ -0,0 +1,61 @@
+using System;
+using System.Buffers.Binary;
+using System.Text;
+using Server;
+using Xunit;
+
+namespace Server.Tests;
+
+public class ObjectPropertyListSpanAddTests
+{
+    // Decodes a terminated OPL buffer into (cliloc, argument) entries.
+    // The OPL packet is big-endian (SpanWriter default), so use BinaryPrimitives.
+    private static (int cliloc, string arg)[] Decode(ObjectPropertyList opl)
+    {
+        opl.Terminate();
+        var buffer = opl.Buffer;
+        var entries = new System.Collections.Generic.List<(int, string)>();
+        var pos = 15; // header is 15 bytes
+        while (true)
+        {
+            var cliloc = BinaryPrimitives.ReadInt32BigEndian(buffer.AsSpan(pos));
+            pos += 4;
+            if (cliloc == 0)
+            {
+                break;
+            }
+
+            var byteLen = BinaryPrimitives.ReadUInt16BigEndian(buffer.AsSpan(pos));
+            pos += 2;
+            var arg = Encoding.Unicode.GetString(buffer, pos, byteLen);
+            pos += byteLen;
+            entries.Add((cliloc, arg));
+        }
+
+        return entries.ToArray();
+    }
+
+    [Fact]
+    public void SpanAdd_ProducesSameBytesAsStringAdd()
+    {
+        var fromString = new ObjectPropertyList(null);
+        fromString.Add("Hello World");
+
+        var fromSpan = new ObjectPropertyList(null);
+        fromSpan.Add("Hello World".AsSpan());
+
+        Assert.Equal(Decode(fromString), Decode(fromSpan));
+        Assert.Equal(fromString.Hash, fromSpan.Hash);
+    }
+
+    [Fact]
+    public void SpanAdd_WithNumber_EmitsClilocAndArgument()
+    {
+        var opl = new ObjectPropertyList(null);
+        opl.Add(1070722, "Custom".AsSpan());
+
+        var entries = Decode(opl);
+        Assert.Single(entries);
+        Assert.Equal((1070722, "Custom"), entries[0]);
+    }
+}
diff --git a/Projects/Server/PropertyList/IPropertyList.cs b/Projects/Server/PropertyList/IPropertyList.cs
index 54b41e4c6..0ab0fc054 100644
--- a/Projects/Server/PropertyList/IPropertyList.cs
+++ b/Projects/Server/PropertyList/IPropertyList.cs
@@ -13,6 +13,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  *************************************************************************/
 
+using System;
 using System.Runtime.CompilerServices;
 using Server.Text;
 
@@ -31,6 +32,9 @@ public interface IPropertyList : ISelfInterpolatedStringHandler
     /** Convenience method for $"{text}". */
     public void Add(string text);
 
+    public void Add(ReadOnlySpan<char> argument);
+    public void Add(int number, ReadOnlySpan<char> argument);
+
     /** Convenience method for $"{value}". */
     public void Add(int number, int value);
 
diff --git a/Projects/Server/PropertyList/ObjectPropertyList.cs b/Projects/Server/PropertyList/ObjectPropertyList.cs
index d1e15abd8..99d538333 100644
--- a/Projects/Server/PropertyList/ObjectPropertyList.cs
+++ b/Projects/Server/PropertyList/ObjectPropertyList.cs
@@ -153,6 +153,40 @@ public sealed class ObjectPropertyList : IPropertyList, IDisposable
     public void AddLocalized(int value) => InternalAdd(GetStringNumber(), $"{value:#}");
     public void AddLocalized(int number, int value) => InternalAdd(number, $"{value:#}");
 
+    public void Add(ReadOnlySpan<char> argument) => InternalAdd(GetStringNumber(), argument);
+    public void Add(int number, ReadOnlySpan<char> argument) => InternalAdd(number, argument);
+
+    private void InternalAdd(int number, ReadOnlySpan<char> chars)
+    {
+        if (number == 0)
+        {
+            return;
+        }
+
+        if (Header == 0)
+        {
+            Header = number;
+            HeaderArgs = chars.ToString();
+        }
+
+        AddHash(number);
+        AddHash(string.GetHashCode(chars, StringComparison.Ordinal));
+
+        var strLength = chars.Length * 2;
+        var length = _bufferPos + 6 + strLength;
+        while (length > _buffer.Length)
+        {
+            Flush();
+        }
+
+        var writer = new SpanWriter(_buffer.AsSpan(_bufferPos));
+        writer.Write(number);
+        writer.Write((ushort)strLength);
+        writer.Write(chars, TextEncoding.UnicodeLE);
+
+        _bufferPos += writer.BytesWritten;
+    }
+
     private int GetStringNumber() => _stringNumbers[_stringNumbersIndex++ % _stringNumbers.Length];
 
     // String Interpolation