Added a recommendation to use s2 in s1 for Python 2.3 and later.

pep-0290.txt

@@ -153,6 +153,17 @@ Modernization Procedures
                 miscounting.
 
 
+    Pattern:    "s1".find("s2") >= 0 or "s1".find("s2") != -1 -> "s2" in "s1"
+    Idea:        In Python 2.3, for "s2" in "s1", the length
+                 restriction on s2 are lifted; they can now be strings
+                 of any length.
+    Version:     2.3 or later
+    Benefits:    When searching for a substring, where you don't care
+                 about the position of the substring in the original
+                 string, using the `in' operator makes things more
+                 clear.
+
+
 References
 
     [1] PEP 4, Deprecation of Standard Modules