diff --git a/QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs b/QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs
index 3a39eef..f262a6c 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs
@@ -25,7 +25,7 @@ namespace QuickLook.Plugin.ArchiveViewer;
 
 public class Plugin : IViewer
 {
-    private static readonly string[] Extensions =
+    private static readonly string[] _extensions =
     [
         ".7z",
         ".bz2",
@@ -50,7 +50,7 @@ public class Plugin : IViewer
 
     public bool CanHandle(string path)
     {
-        return !Directory.Exists(path) && Extensions.Any(path.ToLower().EndsWith);
+        return !Directory.Exists(path) && _extensions.Any(path.ToLower().EndsWith);
     }
 
     public void Prepare(string path, ContextObject context)
diff --git a/QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs b/QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs
index 89daca2..11ca6fd 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs
@@ -25,8 +25,8 @@ namespace QuickLook.Plugin.HtmlViewer;
 
 public class Plugin : IViewer
 {
-    private static readonly string[] Extensions = [".mht", ".mhtml", ".htm", ".html"];
-    private static readonly string[] SupportedProtocols = ["http", "https"];
+    private static readonly string[] _extensions = [".mht", ".mhtml", ".htm", ".html"];
+    private static readonly string[] _supportedProtocols = ["http", "https"];
 
     private WebpagePanel _panel;
 
@@ -38,9 +38,9 @@ public class Plugin : IViewer
 
     public bool CanHandle(string path)
     {
-        return !Directory.Exists(path) && (Extensions.Any(path.ToLower().EndsWith) ||
+        return !Directory.Exists(path) && (_extensions.Any(path.ToLower().EndsWith) ||
                                            path.ToLower().EndsWith(".url") &&
-                                           SupportedProtocols.Contains(Helper.GetUrlPath(path).Split(':')[0]
+                                           _supportedProtocols.Contains(Helper.GetUrlPath(path).Split(':')[0]
                                                .ToLower()));
     }
 
diff --git a/QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs b/QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs
index 07dcd2e..2b13f52 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs
@@ -34,6 +34,23 @@ public class Plugin : IViewer
     private WebpagePanel? _panel;
     private string? _currentHtmlPath;
 
+    /// <summary>
+    /// Markdown and Markdown-like extensions
+    /// It is not guaranteed to support all formats perfectly
+    /// </summary>
+    private static readonly string[] _extensions =
+    [
+        ".md", ".markdown", // The most common Markdown extensions
+        ".mdx", // MDX (Markdown + JSX), used in React ecosystems
+        ".mmd", // MultiMarkdown (MMD), an extended version of Markdown
+        ".mkd", ".mdwn", ".mdown", // Early Markdown variants, used by different parsers like Pandoc, Gitit, and Hakyll
+        ".mdc", // A Markdown variant used by Cursor AI [Repeated format from ImageViewer]
+        ".qmd", // Quarto Markdown, developed by RStudio for scientific computing and reproducible reports
+        ".rmd", ".rmarkdown", // R Markdown, mainly used in RStudio
+        ".apib", // API Blueprint, a Markdown-based format
+        ".mdtxt", ".mdtext", // Less common
+    ];
+
     private static readonly string _resourcePath = Path.Combine(SettingHelper.LocalDataPath, "QuickLook.Plugin.MarkdownViewer");
     private static readonly string _resourcePrefix = "QuickLook.Plugin.MarkdownViewer.Resources.";
     private static readonly ResourceManager _resourceManager = new(_resourcePath, _resourcePrefix);
@@ -51,7 +68,7 @@ public class Plugin : IViewer
 
     public bool CanHandle(string path)
     {
-        return !Directory.Exists(path) && new[] { ".md", ".mdown", ".rmd", ".markdown" }.Any(path.ToLower().EndsWith);
+        return !Directory.Exists(path) && _extensions.Any(path.ToLower().EndsWith);
     }
 
     public void Prepare(string path, ContextObject context)
diff --git a/QuickLook.Plugin/QuickLook.Plugin.PEViewer/Plugin.cs b/QuickLook.Plugin/QuickLook.Plugin.PEViewer/Plugin.cs
index d9350c8..2ae2901 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.PEViewer/Plugin.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.PEViewer/Plugin.cs
@@ -25,7 +25,7 @@ namespace QuickLook.Plugin.PEViewer;
 
 public class Plugin : IViewer
 {
-    private static readonly string[] Extensions =
+    private static readonly string[] _extensions =
     [
         ".exe", ".sys", ".scr", ".ocx", ".cpl",  ".bpl",
         ".dll", ".ax", ".drv", ".vxd",
@@ -46,7 +46,7 @@ public class Plugin : IViewer
 
     public bool CanHandle(string path)
     {
-        return !Directory.Exists(path) && Extensions.Any(path.ToLower().EndsWith);
+        return !Directory.Exists(path) && _extensions.Any(path.ToLower().EndsWith);
     }
 
     public void Prepare(string path, ContextObject context)