diff --git a/memopol/templatetags/memopol_tags.py b/memopol/templatetags/memopol_tags.py
index d7a853bf8e0f66730ae096b2d745a7e986013626..a7522a2648c590468fff972d334aa1930a49223a 100644
--- a/memopol/templatetags/memopol_tags.py
+++ b/memopol/templatetags/memopol_tags.py
@@ -21,6 +21,10 @@ def fix_url(url):
     return re.sub('^(https?://)?', 'https://', url.strip())
 
 
+def cssify(string):
+    return re.sub('[^a-z_-]', '', string.lower())
+
+
 @register.filter
 def twitter_link(url):
     furl = fix_url(url)