a) ILLCC designation. The ILLCC designation consists of:

1. 1) The characters "MF-ILL.C.C." or "MF-ILLCC" (for motor carriers of property) or "ILLCC" or "ILCC" (for all other carriers); and
2. 2) The ILLCC tariff designation number series of each carrier filing tariffs with the Commission, beginning with the Number 1 and subsequent filings being numbered consecutively.

c) Tariff numbers.

1. 1) A tariff number assigned to a tariff shall consist of not more than four numerals.

2. 2) For property tariffs of rail carriers, the first digit or letter shall conform to the grouping in this subsection (2) with the first digit or letter of the tariff being followed by the type of tariff:

   1. A) "1" for class rate tariffs.
   2. B) "2" for class exceptions tariffs.
   3. C) "3" for general commodity rate tariffs (i.e., numerous unrelated commodities).
   4. D) "4" for specific commodity rate tariffs (e.g., iron or steel articles).
   5. E) "5" for routing guide tariffs.
   6. F) "6" for governing tariffs (all kinds).
   7. G) "7" for reserved.
   8. H) "8" or "9" for miscellaneous tariffs (e.g., switching, special service, terminal service).
   9. I) "X" may be used for master tariff of general increases.

3. 3) For tariffs of motor common carriers of property other than household goods carriers the first digit of the tariff number (not the ILLCC tariff designation number) shall conform to the following grouping in this subsection (3):

   1. A) "1" for governing publications of all kinds; adoption notices.
   2. B) "2" for commodity rate tariffs.
   3. C) "3" for combined class and commodity rate tariffs.
   4. D) "4" for commodity column or distance rate tariffs.
   5. E) "5" for class rate tariffs.
   6. F) "6" for miscellaneous tariffs (those not included in any other category).
   7. G) "7" for import and export tariffs (tariffs assigned this digit shall contain only import or export, or both, provisions).
   8. H) "8" for reserved for future assignment.
   9. I) "9" for tariffs containing rates or provisions covering emergency movements authorized by this Commission.
4. 4) When a tariff could be construed as being of more than one type because of the provisions it contains, the governing factor in assignment of the digit or letter will be the category that represents the principal portion of the contents or which signifies its primary purpose, as determined by the carrier or publishing agent.
5. 5) For all tariffs not governed by subsections (c)(2), (3), or (4) of this Section, the carrier or agent shall assign groupings for each of the particular types of tariffs involved, and the number assigned to a tariff shall conform to that grouping.
6. 6) The assigned number will remain the same from reissue to reissue of the tariff. The first time a tariff is issued, its tariff number shall not have a letter suffix. The first reissue of the tariff shall have the letter suffix A, the next reissue B, and so on through Z, after which the letter suffix A will again be used and the process repeated. A carrier or agent may not use any number on its tariffs that differs in any respect from that used in the ILLCC designation, and whole numbers (not fractional or decimal) shall be used.