Publications

Planning Letters 1989

These Informational Letters (IL) or Planning Letters (PL) may be downloaded from this web site. These files require the use of the Adobe Acrobat Reader.

Number Subject Date
IL-89-12-022 NANP - INTERCHANGEABLE CENTRAL OFFICE CODES IN THE MICHIGAN 313 NPA Dec 1989
IL-89-10-072 NANP - INTRODUCTION OF INTERCHANGEABLE CENTRAL OFFICE CODES IN THE 919 NPA Oct 1989
IL-89-10-049 NANP - REVISED NPA MAPS SHOWING NEW NPAS SCHEDULED TO BE INTRODUCED IN 1989 AND 1990 Oct 1989
IL-89-10-048 NANP - INTERCHANGEABLE CENTRAL OFFICE CODES IN THE TORONTO, ONTARIO, CANADA 416 NPA Oct 1989
IL-89-10-047 NANP - INTERCHANGEABLE CENTRAL OFFICE CODES IN THE ARIZONA 602 NPA Oct 1989
IL-89-09-010 NANP - SPLIT OF THE 201 NUMBERING PLAN AREA Sep 1989
IL-89-05-038 NANP - RELIEF OF THE 214 NUMBERING PLAN AREA May 1989
IL-89-04-028 NUMBERING PLAN AREA (NPA) CODE SPLIT IN ILLINOIS Apr 1989
IL-89-02-014 NANP-INTERCHANGEABLE CENTRAL OFFICE CODES IN 404 NPA Feb 1989
IL-88-06-012 NORTH AMERICAN NUMBERING AND DIALING PLANS Jun 1988
IL-88-04-015 NANP - SPLIT OF THE 312 NUMBERING PLAN AREA Apr 1988
IL-87-07-003 NANP - SPLIT OF THE 617 NUMBERING PLAN AREA Jul 1987
IL-87-03-045 NANP - SPLIT OF THE 303 NUMBERING PLAN AREA Mar 1987
IL-87-03-033 NANP - SPLIT OF THE 305 NUMBERING PLAN AREA Mar 1987
IL781-84-04-031 NORTH AMERICAN NUMBERING AND DIALING PLAN Apr 1984

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