diff --git a/param/__init__.py b/param/__init__.py
index <HASH>..<HASH> 100644
--- a/param/__init__.py
+++ b/param/__init__.py
@@ -808,9 +808,6 @@ class Callable(Parameter):
 
 
 
-# CBNOTE: python now has abstract base classes, so we could update
-# this. At least if the check is in a method, all such checks could be
-# changed at once.
 def _is_abstract(class_):
     try:
         return class_.abstract
diff --git a/param/parameterized.py b/param/parameterized.py
index <HASH>..<HASH> 100644
--- a/param/parameterized.py
+++ b/param/parameterized.py
@@ -612,8 +612,8 @@ class ParameterizedMetaclass(type):
         mcs.__param_inheritance(param_name,param)
 
 
-    # CBENHANCEMENT: Python 2.6 has abstract base classes.
-    # http://docs.python.org/whatsnew/2.6.html
+    # Python 2.6 added abstract base classes; see
+    # https://github.com/ioam/param/issues/84
     def __is_abstract(mcs):
         """
         Return True if the class has an attribute __abstract set to True.
Replaced comment with link to github issue.