--- Config.py
+++ Config.py
@@ -115,6 +115,8 @@
 # List of filters
 _filters = []
 _filters_re = None
+_filters_except = []
+_filters_except_re = None
 
 def addFilter(s):
     global _filters
@@ -137,8 +139,14 @@
 _scoring = {}
 
 def setBadness(s, score):
+    global _scoring
     _scoring[s] = score
 
+def setFilterException(s):
+    global _filters_except
+
+    _filters_except.append(s)
+
 def badness(s):
     return _scoring.get(s, 0)
 
@@ -146,6 +154,8 @@
 def isFiltered(s):
     global _filters
     global _filters_re
+    global _filters_except
+    global _filters_except_re
 
     if _filters_re == None:
         # no filter
@@ -162,7 +172,21 @@
             _filters_re = _filters_re + '|(?:' + _filters[idx] +')'
         _filters_re = re.compile(_filters_re)
 
+    if _filters_except_re == None and len(_filters_except):
+        _filters_except_re = '(?:' + _filters_except[0] + ')'
+
+        for idx in range(1, len(_filters_except)):
+            # to prevent named group overflow that happen when there is too
+            # many () in a single regexp: AssertionError: sorry, but this
+            # version only supports 100 named groups
+            if '(' in _filters_except[idx]:
+                _non_named_group_re.subn('(:?', _filters_except[idx])
+            _filters_except_re = _filters_except_re + '|(?:' + _filters_except[idx] +')'
+        _filters_except_re = re.compile(_filters_except_re)
+
     if not no_exception:
+        if _filters_except_re and _filters_except_re.search(s):
+            return False
         if _filters_re.search(s):
             return True
     return False