CORES REGISTRATION
(This information from article by Steve Devine, KC0BXQ)
Note: when at the ARRL Website, you can type your call in the Call Sign Search and hit enter.  The Data provided is from the FCC Database and if you have an FRN number assigned it will be part of the data.
           If you registered your ULS prior to June 2000 ,  you   probably  have already been assigned your (FRN) number.  You can   check on this  if you have a Netscape Browser at       http://www.fcc.gov/wtb/uls
      Once the page is loaded, click on TIN/CALLSIGN. After that  page loads,  click  on "Update Registration Information" and click  Continue.  At the next  screen, enter your social security number  (no dashes) in the field labeled  "Taxpayer Identifiction Number" and  then TAB down to "Password"  Enter  your password (You Remember  it don't you?) and click continue.  The next screen that appears should  show your ULS registration information.    The first line shows  your SSN, the Second line show your FRN if you are registered  with CORES.  If the Field is blank, you MUST register in CORES.    
   If you need to be assigned a FRN, go to  https://svartifoss2.fcc.gov/cores/CoresHome.html and follow the on-screen prompts.  This should provide the required information to get your ULS/CORES number assigned.  The FCC should assign you a FRN number when the Dec 3, 2001 actions occur.  Once you have been issued your FRN (it should   be on the last page you'll see when you are registering) PRINT IT OUT  and then SAVE IT and your PASSWORD in a safe place.

FCC Registration Number  Password Problems
(This information from article by Steve Devine, KC0BXQ)

Why is a password required?
Since the FRN is public information, a password ensures that only you or another authorized person can gain access or make a change to your data.

Assigning Passwords
Your password is kept confidential and is case sensitive. It should have a minimum of
six characters and a maximum of 15 characters. When you register on the web, you
select your  own password between 6 and 15 characters. You may also select a password hint if you choose. If you elect not to choose your own password or hint, CORES will select one for you. A password hint is a word or words that can help you remember your password. For instance, if you've selected Tommy after your son, you might choose "my son" as your hint. The password, hint, and FRN will appear on the final Registration Confirmation page. You should print this out and keep it in a safe place for future reference.
If you register by mail, CORES selects your password for you. You will receive a confirmation letter giving you your  password and FRN. After receiving the notification letter, you can modify your password on-line with CORES.  If you were one of the ULS users that the FCC pre-registered with CORES, you will have received a letter that was mailed to your ULS contact giving them the password and FRN.

If I forget my password, how do I find out what it is?
It's a lot of trouble so try to try to keep your password in a safe place. If all else fails then you must contact the CORES Administrator at 877-480-3201. You will be asked to     provide your FRN and TIN. (TIN is your Social Security Number )  After you provide the right  information to the CORES Administrator, he/she will give you three options to choose from.

    1. They'll give you the password with the hint.

    2. They will reset your password to one generated by CORES
       and send you the new password information in the mail.

    3. They will assign you a temporary password over the phone
       that's good for 20 minutes. If you choose this option, it
       will be necessary for you to go to the CORES website
       Update option and change your temporary password within
       20 minutes of when it was issued.
Can any browser access your FCC CORES site?
Netscape 3.x or higher, or MS Internet Explorer 3.x or higher work equally well.

Can you register for an FRN without the Internet?
There is also a manual registration process available. You can download the forms via the web by using the FCC's form download page at the FCC's Home page. You can also request the forms through the fax-on-demand at 202-418-0177 or call the FCC copy contractor, International Transcription.  Services, Inc. (ITS) at 202-857-3800. You will be required to provide the same information as if you registered on-line. You can mail the form manually to:

       FCC
       CORES Administrator
       445 12th St., SW
       Room CY-C140
       Washington DC 20554

  CORES Forms:
    Form 160       CORES Manual Registration Form
    Form 161       CORES Update/Change Form
    Form 162       CORES Certification Form

If you were given an FRN as the result of having taken a recent FCC exam and you want to know  your FRN, and the CORES assigned password you need to call the CORES Help Desk  at     877-480-3201    CORES Hours    8am-6pm Eastern Time

E-mail for Help     [email protected]  888-225-5322   FCC Consumer Center