Italicise parameter reference

Author: sebbASF

Doc/library/mailbox.rst

@@ -589,25 +589,25 @@ Supported mailbox formats are Maildir, mbox, MH, Babyl, and MMDF.
 
    .. method:: get_bytes(key, from_=False)
 
-      Note: This method has an extra parameter (from_) compared with other classes.
+      Note: This method has an extra parameter (*from_*) compared with other classes.
       The first line of an mbox file entry is the unix 'From ' line.
-      If from_ is False, the first line of the file is dropped.
+      If *from_* is False, the first line of the file is dropped.
 
    .. method:: get_file(key, from_=False)
 
       Using the file after calling :meth:`~Mailbox.flush` or
       :meth:`~Mailbox.close` on the :class:`!mbox` instance may yield
       unpredictable results or raise an exception.
 
-      Note: This method has an extra parameter (from_) compared with other classes.
+      Note: This method has an extra parameter (*from_*) compared with other classes.
       The first line of an mbox file entry is the unix 'From ' line.
-      If from_ is False, the first line of the file is dropped.
+      If *from_* is False, the first line of the file is dropped.
 
    .. method:: get_string(key, from_=False)
 
-      Note: This method has an extra parameter (from_) compared with other classes.
+      Note: This method has an extra parameter (*from_*) compared with other classes.
       The first line of an mbox file entry is the unix 'From ' line.
-      If from_ is False, the first line of the file is dropped.
+      If *from_* is False, the first line of the file is dropped.
 
    .. method:: lock()
                unlock()