1 Pa. Code § 35.9
A person complaining of anything done or omitted to be done by a person subject to the jurisdiction of an agency, in violation of a statute or regulation administered or issued by the agency may file a complaint with the agency. If the complaint relates to a provision in a tariff, policy form or other similar contract document on file with the agency, the document should be identified. A copy of the complaint will be forwarded by the agency to the respondent who will be called upon to satisfy the complaint or to answer the same in writing within the time specified in § 35.35 (relating to answers to complaints and petitions), or such lesser time as may be prescribed by statute, after the date of service of the complaint, unless the agency with or without motion shall prescribe a different time. If, in the judgment of the agency, a violation of a statute or regulation administered or issued by the agency has been alleged and has not been satisfied adequately the agency will either invite the parties to an informal conference, set the matter for a formal hearing, or take another action which in the judgment of the agency is appropriate. In the event that a hearing is held the complainant automatically shall be a party thereto and need not file a petition for leave to intervene.
1 Pa. Code § 35.9
This section cited in 1 Pa. Code § 35.5 (relating to form and content of informal complaints); 4 Pa. Code § 105.12 (relating to requests); 7 Pa. Code § 179.13 (relating to complaints and other pleadings); 12 Pa. Code § 11.7 (relating to complaints); 22 Pa. Code § 351.1 (relating to purpose and scope); 25 Pa. Code § 1021.51 (relating to commencement, form and content); 25 Pa. Code § 1021.52 (relating to timeliness of appeal); 25 Pa. Code § 1021.53 (relating to amendments to appeal or complaint); 25 Pa. Code § 1021.71 (relating to complaints filed by the Department); 25 Pa. Code § 1021.72 (relating to complaints filed by other persons); 25 Pa. Code § 1021.73 (relating to transferred matters); 34 Pa. Code § 81.71 (relating to filing); 34 Pa. Code § 111.15 (relating to no other pleadings allowed); 34 Pa. Code § 131.32 (relating to petitions except petitions for joinder and challenge proceedings); 34 Pa. Code § 131.121 (relating to penalty proceedings initiated by a party); 37 Pa. Code § 171.44 (relating to supporting legal authority); 37 Pa. Code § 421.21 (relating to reconsideration of adverse determination and request for hearing); 51 Pa. Code § 21.1 (relating to complaints); 52 Pa. Code § 5.21 (relating to formal complaints generally); 52 Pa. Code § 1005.11 (relating to formal complaints generally); 52 Pa. Code § 1005.12 (relating to content of formal complaints); 52 Pa. Code § 1005.13 (relating to citation complaints by the Authority); 55 Pa. Code § 41.31 (relating to request for hearing); 55 Pa. Code § 41.32 (relating to timeliness and perfection of requests for hearing); 55 Pa. Code § 41.33 (relating to appeals nunc pro tunc); 58 Pa. Code § 493a.1 (relating to generally); 58 Pa. Code § 493a.2 (relating to complaints); and 61 Pa. Code § 703.5 (relating to other submissions).