Default is to reject redirection status code (301/302 and 304). This is usually cached pages (browser cache or proxy). It's very easy to cheat stats reports, increasing numbers, just using your browser's reload button. These are pages seen by users and not send by server. if you want to count these redirection status code, your stats reports will show larger numbers but will not reflect user's usage.

Squid reports show redirection status code because Squid IS a proxy (some king of large cache). So it's useful to know how much files have been cached and how many have been requested.

Status code Associated Message Meaning
Redirect
300 Multiple Choices This code informs users and user agents that the resource is available at multiple locations, perhaps in different representations.
301 Moved Permanently This code redirects clients to a new location for the requested resource. This happens often when people relocate files on their servers, or when content is moved from one server to another. Because the redirection is permanent, clients and caches can remember the new location and automatically redirect future requests.
302 Moved Temporarily This code is a temporary redirect to a new location. Apparently, many user agents always issue GET requests for the new URI, regardless of the original request method. This action violates even the older HTTP RFCs (1945 and 2068), but has become the expected behavior. RFC 2616 added two new status codes, 303 and 307, to ``fix'' this problem.
303 See Other This code is the same as 302, except that the client should make a GET request for the new URI, regardless of the original request method.
304 Not Modified This code is used when the client makes a conditional GET request (e.g. If-modified-since) and the resource has not changed.
305 Use Proxy This code allows origin servers to redirect requests through a caching proxy. The proxy's address is given in the Location header.
306 Unused A search of the HTTP working group archives reveals that, at one time, this code was named Switch Proxy.
307 Temporary Redirect This code is similar to 302, indicating a temporary new location for the resource. However, clients must not use a different request method when requesting the new URI.