In response to a question from a possible host site, I've added some text to
the Code4Lib Conference Hosting page at
<http://www.code4lib.org/conference/hosting>:

What the Hosting Site is Not Responsible For

These items are the responsibility of the Code4Lib Conference planning group
(anyone on the conference planning list, which is open to anyone), but the
conference host is often actively involved with these aspects as well:

    * Planning the conference program
    * Signing on conference sponsors

I believe this is just codifying existing practice, but I'm posting this
here in case anyone has any corrections or additions.
Roy