Index: /pyyaml/trunk/lib/yaml/resolver.py
===================================================================
--- /pyyaml/trunk/lib/yaml/resolver.py	(revision 223)
+++ /pyyaml/trunk/lib/yaml/resolver.py	(revision 226)
@@ -154,5 +154,5 @@
 Resolver.add_implicit_resolver(
         u'tag:yaml.org,2002:bool',
-        re.compile(ur'''^(?:yes|Yes|YES|n|N|no|No|NO
+        re.compile(ur'''^(?:yes|Yes|YES|no|No|NO
                     |true|True|TRUE|false|False|FALSE
                     |on|On|ON|off|Off|OFF)$''', re.X),
Index: /pyyaml/trunk/tests/data/construct-bool.data
===================================================================
--- /pyyaml/trunk/tests/data/construct-bool.data	(revision 59)
+++ /pyyaml/trunk/tests/data/construct-bool.data	(revision 226)
@@ -3,2 +3,7 @@
 logical: True
 option: on
+
+
+but:
+    y: is a string
+    n: is a string
Index: /pyyaml/trunk/tests/data/construct-bool.code
===================================================================
--- /pyyaml/trunk/tests/data/construct-bool.code	(revision 58)
+++ /pyyaml/trunk/tests/data/construct-bool.code	(revision 226)
@@ -4,3 +4,4 @@
     "logical": True,
     "option": True,
+    "but": { "y": "is a string", "n": "is a string" },
 }