The first two digits of the year are packed into a single character in column 1 (I = 18, J = 19, K = 20). Columns 2-3 contain the last two digits of the year. Column 4 contains the half-month letter and column 7 contains the second letter. The cycle count (the number of times that the second letter has cycled through the alphabet) is coded in columns 5-6, using a letter in column 5 when the cycle count is larger than 99. The uppercase letters are used, followed by the lowercase letters.
Where possible, the cycle count should be displayed as a subscript when the designation is written out in unpacked format.
Examples: J95X00A = 1995 XA J95X01L = 1995 XL1 J95F13B = 1995 FB13 J98SA8Q = 1998 SQ108 J98SC7V = 1998 SV127 J98SG2S = 1998 SS162 K99AJ3Z = 2099 AZ193 K08Aa0A = 2008 AA360 K07Tf8A = 2007 TA418Survey designations of the form 2040 P-L, 3138 T-1, 1010 T-2 and 4101 T-3 are packed differently. Columns 1-3 contain the code indicating the survey and columns 4-7 contain the number within the survey.
Examples: 2040 P-L = PLS2040 3138 T-1 = T1S3138 1010 T-2 = T2S1010 4101 T-3 = T3S4101
Examples: 1995 A1 = J95A010 1994 P1-B = J94P01b refers to fragment B of 1994 P1 1994 P1 = J94P010 refers to the whole comet 1994 P1 2048 X13 = K48X130 2033 L89-C = K33L89c 2088 A103 = K88AA30 A3 = 103Comet designations may also be given in a 12-character form, where columns 6-12 are as described above. Column 5 will contain a `C', `P', `D' or `X' (depending on the status and orbit type of the comet). For a numbered periodic comet, columns 1-4 contain the periodic-comet number, left-padded with zeroes. For other comets columns 1-4 contain blanks.