make suggested changes.

docs/topics/logging.rst

@@ -193,11 +193,13 @@ to override some of the Scrapy settings regarding logging.
     Module `logging.handlers <https://docs.python.org/2/library/logging.handlers.html>`_
         Further documentation on available handlers
 
-Custom Log Formats
--------------------
+.. _custom-log-formats:
 
-Custom log format can be set for different actions by extending :class:`~scrapy.logformatter.LogFormatter` class
-and making :setting:`LOG_FORMATTER` inside ``settings.py`` point to your new class.
+Custom Log Formats
+------------------
+
+A custom log format can be set for different actions by extending :class:`~scrapy.logformatter.LogFormatter` class
+and making :setting:`LOG_FORMATTER` point to your new class.
  
 .. autoclass:: scrapy.logformatter.LogFormatter
    :members:

docs/topics/settings.rst

@@ -871,9 +871,9 @@ directives.
 LOG_FORMATTER
 -------------
 
-Default: ``scrapy.logformatter.LogFormatter``
+Default: :class:`scrapy.logformatter.LogFormatter`
 
-The class to use for formatting log messages for different actions.
+The class to use for :ref:`formatting log messages <custom-log-formats>` for different actions.
 
 .. setting:: LOG_LEVEL
 

scrapy/logformatter.py

@@ -30,12 +30,24 @@ class LogFormatter(object):
         *   ``args`` should be a tuple or dict with the formatting placeholders for ``msg``. The final log message is
             computed as ``msg % args``.
 
+    Here is an example on how to create a custom log formatter to lower the severity level of the log message
+    when an item is dropped from the pipeline::
+
+            class PoliteLogFormatter(logformatter.LogFormatter):
+                def dropped(self, item, exception, response, spider):
+                    return {
+                        'level': logging.INFO, # lowering the level from logging.WARNING
+                        'msg': u"Dropped: %(exception)s" + os.linesep + "%(item)s",
+                        'args': {
+                            'exception': exception,
+                            'item': item,
+                        }
+                    }
+
     """
 
     def crawled(self, request, response, spider):
-        """
-        ``crawled`` is called to log message when the crawler finds a webpage.
-        """
+        """Logs a message when the crawler finds a webpage."""
         request_flags = ' %s' % str(request.flags) if request.flags else ''
         response_flags = ' %s' % str(response.flags) if response.flags else ''
         return {
@@ -53,9 +65,7 @@ class LogFormatter(object):
         }
 
     def scraped(self, item, response, spider):
-        """
-        ``scraped`` is called to log message when an item is scraped by a spider.
-        """
+        """Logs a message when an item is scraped by a spider."""
         if isinstance(response, Failure):
             src = response.getErrorMessage()
         else:
@@ -70,9 +80,7 @@ class LogFormatter(object):
         }
 
     def dropped(self, item, exception, response, spider):
-        """
-        ``dropped`` is called to log message when an item is dropped while it is passing through the item pipeline. 
-        """
+        """Logs a message when an item is dropped while it is passing through the item pipeline."""
         return {
             'level': logging.WARNING,
             'msg': DROPPEDMSG,