Added one-line comments to the proto 2 opcodes.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index 27d28eb..2d6710b 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -133,20 +133,20 @@
TRUE = 'I01\n' # not an opcode; see INT docs in pickletools.py
FALSE = 'I00\n' # not an opcode; see INT docs in pickletools.py
-# Protocol 2 (not yet implemented) (XXX comments will be added later)
+# Protocol 2 (not yet implemented).
-PROTO = '\x80'
-NEWOBJ = '\x81'
-EXT1 = '\x82'
-EXT2 = '\x83'
-EXT4 = '\x84'
-TUPLE1 = '\x85'
-TUPLE2 = '\x86'
-TUPLE3 = '\x87'
-NEWTRUE = '\x88'
-NEWFALSE = '\x89'
-LONG1 = '\x8a'
-LONG4 = '\x8b'
+PROTO = '\x80' # identify pickle protocol
+NEWOBJ = '\x81' # build object by applying cls.__new__ to argtuple
+EXT1 = '\x82' # push object from extension registry; 1-byte index
+EXT2 = '\x83' # ditto, but 2-byte index
+EXT4 = '\x84' # ditto, but 4-byte index
+TUPLE1 = '\x85' # build 1-tuple from stack top
+TUPLE2 = '\x86' # build 2-tuple from two topmost stack items
+TUPLE3 = '\x87' # build 3-tuple from three topmost stack items
+NEWTRUE = '\x88' # push True
+NEWFALSE = '\x89' # push False
+LONG1 = '\x8a' # push long from < 256 bytes
+LONG4 = '\x8b' # push really big long
__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)])