diff --git a/Program.cs b/Program.cs
index 481cddd..41d43e8 100644
--- a/Program.cs
+++ b/Program.cs
@@ -64,7 +64,14 @@ namespace ComicCompressor
         // In core changed color of percent save to white
         //string progVersion = "Version 3.0.1 - (23/01/2025)";
 
-        // In core changed color of percent save to white
+        // Updated NuGet packages (SharpCompress 0.49, Magick.NET 14.14, System.Drawing.Common 10.0,
+        //   itext 9.6, Imazen.WebP 11.0, McMaster 5.1). SharpCompress 0.49 API migration.
+        // Pre-sized MemoryStream allocations with entry.Size (reduced GC pressure).
+        // Fixed missing OnExecuteAsync (CLI was throwing InvalidOperationException on launch).
+        // Added -w|--new-webp flag (Imageflow encoder; benchmarked slower than Imazen.WebP).
+        // Added -x|--par-archive: parallel image compression within archive (~4-5x speedup).
+        //   Batched 3-phase: sequential read → Parallel.For (ProcessorCount/2) → sequential write.
+        // GUI: added Par.Archive checkbox (default ON for COMIX/COMIX+PDF modes).
         string progVersion = "Version 3.1.0 - (27/06/2027)";
         public static int Main(string[] args) => CommandLineApplication.Execute<Program>(args);
 
@@ -108,7 +115,7 @@ namespace ComicCompressor
         [Option("-w|--new-webp", Description = "Use Imageflow encoder (faster JPEG→WebP transcoding, no full pixel decode)")]
         public bool NewWebp { get; } = false;
 
-        [Option("-P|--par-archive", Description = "Parallel image compression within each archive (~4-5x faster, uses half the CPUs)")]
+        [Option("-x|--par-archive", Description = "Parallel image compression within each archive (~4-5x faster, uses half the CPUs)")]
         public bool ParArchive { get; } = false;
 
         #endregion