The Schools and Libraries Division (SLD) has posted a note (dated 10/21/04) that entities applying for E-Rate will need an "FCC Registration Number" or FCC RN. (http://www.sl.universalservice.org/). The instructions explain what information needs to be provided.
If you follow the link provided on the page noted above, it leads to the instructions for how to secure this new registration number. Note that you will be required to enter your school's Taxpayer Identification Number, so have that handy when you go to the FCC site (http://www.fcc.gov/). The link to create the Registration Number is on the left side of the page.
There is currently no space for this neww FCC number to be entered on either the Form 470 or 471, but if the SLD needs to contact you concerning your upcoming E-Rate application, they will probably ask for your FCC Registration Number.
The process for acquiring the FCC Registration Number is pretty quick - about a minute or so.