diff --git a/html_cleanup/views/default.py b/html_cleanup/views/default.py
index a7b1432..c5a3b2d 100644
--- a/html_cleanup/views/default.py
+++ b/html_cleanup/views/default.py
@@ -134,7 +134,8 @@ def clean_html(input_file, output_file):
     #20260104: removed "span", </span>
     #20260122: move the function check_input_name into the function clean_html as inner function
     #20260128: removed text-align:justify in <p>
-    #version: 3_5_3_3
+    #20260129: added strikethrough tag: <s>, <del>, <ins>: insert with underline
+    #version: 3_5_3_5
 
     def check_input_name(attribute):
         ret_flag=False
@@ -157,7 +158,6 @@ def clean_html(input_file, output_file):
             nb_lines = 0
 
             for line_in in fi:
-                line_in = html.unescape(line_in)
                 line_out = ""
 
                 if not body:
@@ -235,7 +235,7 @@ def clean_html(input_file, output_file):
 
                                     elif tag[0] in ["b", "/b", "em", "/em", "i", "/i", "li", "/li", "ol", "/ol",
                                                     "ul", "/ul", "strong", "/strong", "sub", "/sub", "sup", "/sup",
-                                                    "u", "/u"]:
+                                                    "u", "/u", "s", "/s", "del", "/del", "ins", "/ins"]:
                                         line_out += "<{}>".format(tag[0])
                                     elif tag[0] in ["/h1", "/h2", "/h3", "/h4", "/h5",  "/h6", "/p",
                                                     "body", "/body", "/html", "/div", "/img", "/a"]:
@@ -244,7 +244,7 @@ def clean_html(input_file, output_file):
                                         line_out += "<{}>".format(tag[0])
                                     elif tag[0] in ["br", "br/", "hr"]:
                                         line_out += "<{}>".format(tag[0])
-
+                
                         if line_out != "":
                             fo.write(line_out + "\n")