The history parameter specifies whether or not the URL that you are
shortening will show up in your history if you were signed into
bit.ly. As for the custom name parameter, we'll be exposing an API to
allow you to specify this when we roll out user space keywords. For
example:
http://nate.bit.ly/keyword. We haven't exposed this so far
because we were concerned people would abuse the API and grab all
available keywords. Hope that helps!
- Nathan