As used in this part:

1. (1) "Acts" means, unless the context otherwise indicates, any statute which the State Highway Commission administers in whole or in part;
2. (2) "Applicant" means a person filing an application;
3. (3) "Defendant" means a carrier or other person against whom a complaint is filed;
4. (4) "Interested parties" shall in all cases include all carriers operating over the routes or any part thereof or in the territory involved in any application for a certificate of convenience and necessity or permit, or any application to file or change any schedule of rates, charges, fares, or any rule, regulations, or practice, and such other parties as may be deemed interested in the particular matter;
5. (5) "Intervener" means a person permitted to intervene;
6. (6) "Officer" means a commissioner or other person empowered by the State Highway Commission to act for it;
7. (7) ''Petitioner" means any person seeking relief otherwise than by complaint or application;
8. (8) "Plaintiff” means a person filing a complaint;

9. (9) "Pleading" means:

   1. (A) A complaint;
   2. (B) An answer;
   3. (C) A reply;
   4. (D) An application;
   5. (E) A protest;
   6. (F) A motion other than motion orally made at a hearing or argument;
   7. (G) A petition; or
   8. (H) A document supplementing oral hearing;

10. (10) "Proceeding" shall include:

    1. (A) An informal or formal complaint alleging violation of any provision of any act or of any rule, regulation, or requirements made pursuant to a power granted by such act, including petitions;

    2. (B) An application for:

       1. (i) The granting of any right, privilege, authority, or relief under or from any provision of any act or of any rule or requirement made pursuant to a power granted by such act; or
       2. (ii) The consideration of any submission required by law to be made to the State Highway Commission;
    3. (C) An investigation instituted, or requested to be instituted, by the State Highway Commission;
    4. (D) Modified procedure;
    5. (E) Show cause orders;
    6. (F) Rulemaking; and
    7. (G) Promulgation of rules and procedures for assessing public carriers and review of assessments of public carriers;
11. (11) "Protestant" means a person opposed to the granting of an application, or to any tariff or schedule becoming effective; and
12. (12) "Respondent" means a person designated in an investigation.