Publications

Planning Letters 1990

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-90-12-050 NANP - REMINDER OF FEBRUARY 1, 1991 DATE FOR ELIMINATION OF THE USE OF THE 706 AND 905 NPA CODES FOR CALLS TO MEXICO Dec 1990
IL-90-12-049 NANP - SPLIT OF THE 301 (MARYLAND) NUMBERING PLAN AREA (NPA) Dec 1990
IL-90-08-055 NANP - SPLIT OF 213 (CALIFORNIA) NUMBERING PLAN AREA Aug 1990
IL-90-08-052 NANP - REMINDER OF NUMBERING PLAN AREA (NPA) CODE SPLITS IN TEXAS AND NEW JERSEY Aug 1990
IL-90-07-004 NANP - INTRODUCTION OF INTERCHANGEABLE CENTRAL OFFICE CODES IN THE 215 NPA Jul 1990
IL-90-06-023 NANP - REVISED DATE FOR SPLIT OF 415 (CALIFORNIA) NUMBERING PLAN AREA Jun 1990
IL-90-04-003 NANP - INTRODUCTION OF DIALING PROCEDURE CHANGES IN THE 202 AND PORTIONS OF THE 301 AND 703 NUMBERING PLAN AREA (NPAS) Apr 1990
IL-90-04-002 NANP - INTRODUCTION OF INTERCHANGEABLE CENTRAL OFFICE CODES IN THE 205 NPA Apr 1990
IL-90-04-001 NANP - INTRODUCTION OF INTERCHANGEABLE CENTRAL OFFICE CODES IN THE 512 NPA Apr 1990

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