SEC. 2. TAPE SPECIFICATIONS

.01 In most instances, IRS/MCC can process any compatible tape files. Compatible tape files must meet any one set of the following:

(a) 9-track EBCDIC (Extended Binary Coded Decimal Interchange Code) with;

(1) Odd Parity and (2) A density of 1600 or 6250 BPI. (3) If you use Unisys Series 1100, you must submit an interchange tape. (b) 9-track ASCII (American Standard Coded Information Interchange) with;

(1) Odd Parity and (2) A density of 1600 or 6250 BPI.

December 6, 1999 612 1999–49 I.R.B.

Please be consistent in the use of recording codes and density on your files. If files are generated in more than one recording code and/or density, multiple shipments would be appreciated.

.02 All compatible tape files must have the following characteristics:

(a) ¹ ⁄2 inch mylar base, oxide coated; computer grade magnetic tape on reels up to 2400 feet (731.52 m) within the following

specifications: (1) Tape thickness: 1.0 or 1.5 mils (2) Reel diameter: 10.5 inch (26.67 cm), 8.5 inch (21.59 cm), or 7 inch (17.78 cm). .03 All records have a fixed record length of 372 positions. .04 The tape record defined in this revenue procedure may be blocked or unblocked, subject to the following:

(a) All records except the header and trailer labels may be blocked. (b) If records are blocked, the block can not exceed 32,736 tape positions. The block length must be evenly divisible by 372 (c) If the use of blocked records would result in a short block, all remaining positions of the block MUST be filled with 9’s.

DO NOT PAD A BLOCK WITH BLANKS. Padding a block with blanks will result in a short record, which will cause math computation errors. Your tape will then be returned for replacement. .05 For the purposes of this revenue procedure, the following conventions must be used: Header label:

(a) Transmitters may use standard headers provided they begin with 1HDR, HDR1, VOL1, or VOL2. (b) Consists of a maximum of 80 positions. (c) Header and trailer labels are optional unless more than one reel is being submitted. If more than one reel is being submitted,

header and trailer labels are required. IRS/MCC PREFERS STANDARD OR ANSI LABELED TAPES. IF YOU SUBMIT AN UNLABELED TAPE, THIS MUST BE INDICATED ON THE EXTERNAL LABEL AND ON THE FORM 4804 OR COMPUTERGENERATED SUBSTITUTE. Trailer label:

(a) Standard trailer labels may be used provided that they begin with 1EOR, 1EOF, EOV1, or EOV2. (b) Consists of a maximum of 80 positions. (c) Header and trailer labels are optional unless more than one reel is being submitted. If more than one reel is being submit

ted, header and trailer labels are required. Tape Mark:

(a) Used to signify the physical end of the recording on tape. (b) May follow the header label and precede and/or follow the trailer label.