[Mediawiki-api] maximum revisions per query request

[randomcoder1 at gmail.com]

I'm interested in the biggest number of revisions I can get through a 
single request.
The documentation here http://en.wikipedia.org/w/api.php says that 
rvlimit would be a good parameter to pass if you want
to fetch some revisions of an article and you want to set the number of 
revisions you receive :

  rvlimit        - limit how many revisions will be returned (enum)
                   No more than 500 (5000 for bots) allowed.

I tried that myself and only got to at most 50 revisions per request.
Can I get more than 50 revisions per request ?
I understand that the program I'm running must be identified as a bot.
Do I have to make an account for it and set in the notify wikipedia that it is a bot ?
How can this notification be made ?
What other 'benefits' does a bot have ?

Thank you