diff --git a/boltons/strutils.py b/boltons/strutils.py
index 9c555af..5bb265f 100644
--- a/boltons/strutils.py
+++ b/boltons/strutils.py
@@ -14,19 +14,41 @@ def slugify(text, delim='_'):
     lowercased string separated only by the delimiter specified
     by 'delim', which defaults to '_'.
 
-    >>> 'First post! Hi!!!!~1    '
+    >>> slugify('First post! Hi!!!!~1    ')
     'first_post_hi_1'
     """
     return delim.join(split_punct_ws(text)).lower()
 
 
 def split_punct_ws(text):
+    """
+    str.split() will split on whitespace, split_punct_ws will
+    split on punctuation and whitespace. This is mostly here
+    for use by slugify(), above.
+
+    >>> split_punct_ws('First post! Hi!!!!~1    ')
+    ['First', 'post', 'Hi', '1']
+    """
     return [w for w in _punct_re.split(text) if w]
 
 
-def camel2under(string):
-    return _camel2under_re.sub(r'_\1', string).lower()
+def camel2under(camel_string):
+    """
+    Converts a camelcased string to underscores. Useful for
+    turning a class name into a function name.
+
+    >>> camel2under('BasicParseTest')
+    'basic_parse_test'
+    """
+    return _camel2under_re.sub(r'_\1', camel_string).lower()
 
 
-def under2camel(string):
-    return ''.join(w.capitalize() or '_' for w in string.split('_'))
+def under2camel(under_string):
+    """
+    Converts an underscored string to camelcased. Useful for
+    turning a function name into a class name.
+
+    >>> under2camel('complex_tokenizer')
+    'ComplexTokenizer'
+    """
+    return ''.join(w.capitalize() or '_' for w in under_string.split('_'))