Bid Filing

At least 180 days before the opening of the administering convention a Worldcon bid is required to file if it wants to be on the site selection ballot. The details of the filing are specified in section 4.6.1 of the WSFS Constitution:

4.6.1. To be eligible for site selection, a bidding committee must file the following documents with the Committee that will administer the voting:
(1) an announcement of intent to bid;
(2) adequate evidence of an agreement with its proposed site's facilities, such as a conditional contract or a letter of agreement;
(3) the rules under which the Worldcon Committee will operate, including a specification of the term of office of their chief executive officer or officers and the conditions and procedures for the selection and replacement of such officer or officers.

As you'd expect, these provisions were added because bids had failed to have agreements with adequate facilities or had left their organization unspecified and this had led to problems.

These documents are public.

See Worldcon bidding process for context.