diff --git a/IPython/core/history.py b/IPython/core/history.py
index 7734780..9a4a249 100644
--- a/IPython/core/history.py
+++ b/IPython/core/history.py
@@ -762,8 +762,10 @@ def magic_history(self, parameter_s = ''):
       the default is the last 10 lines.
 
       -f FILENAME: instead of printing the output to the screen, redirect it to
-       the given file.  The file is always overwritten, though IPython asks for
-       confirmation first if it already exists.
+       the given file.  The file is always overwritten, though *when it can*,
+       IPython asks for confirmation first. In particular, running the command
+       "history -f FILENAME" from the IPython Notebook interface will replace
+       FILENAME even if it already exists *without* confirmation.
 
     Examples
     --------
@@ -801,12 +803,11 @@ def magic_history(self, parameter_s = ''):
             try:
                 ans = io.ask_yes_no("File %r exists. Overwrite?" % outfname)
             except StdinNotImplementedError:
-                print("Overwriting file.")
                 ans = True
             if not ans:
                 print('Aborting.')
                 return
-
+            print("Overwriting file.")
         outfile = open(outfname,'w')
         close_at_end = True
 
diff --git a/IPython/core/magic.py b/IPython/core/magic.py
index 39e66b5..950a1e5 100644
--- a/IPython/core/magic.py
+++ b/IPython/core/magic.py
@@ -984,6 +984,12 @@ Currently the magic system has the following functions:\n"""
 
         In [1]: 'a' in _ip.user_ns
         Out[1]: False
+
+        Notes
+        -----
+        Calling this magic from clients that do not implement standard input,
+        such as the ipython notebook interface, will reset the namespace
+        without confirmation.
         """
         opts, args = self.parse_options(parameter_s,'sf')
         if 'f' in opts:
@@ -1056,6 +1062,12 @@ Currently the magic system has the following functions:\n"""
 
         In [11]: who_ls
         Out[11]: ['a']
+
+        Notes
+        -----
+        Calling this magic from clients that do not implement standard input,
+        such as the ipython notebook interface, will reset the namespace
+        without confirmation.
         """
 
         opts, regex = self.parse_options(parameter_s,'f')