1 Pa. Code § 35.5
Informal complaint may be by letter or other writing, and shall be serially numbered and filed as of the date of its receipt. No form of informal complaint is suggested, but in substance the letter or other writing shall contain the essential elements of a formal complaint as specified in § 35.9 (relating to formal complaints generally). Only one copy of an informal complaint need be filed. It may embrace supporting papers.
1 Pa. Code § 35.5
This section cited in 6 Pa. Code § 3.5 (relating to informal complaints); 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 amendment to appeal or complaint); 25 Pa. Code § 1021.71 (relating to complaints filed by the Department); 25 Pa. Code § 1021.72 (relating to answers to complaints filed by other persons); 25 Pa. Code § 1021.73 (relating to transferred matters); 25 Pa. Code § 1021.74 (relating to answers to complaints); 28 Pa. Code § 1230.38 (relating to commencement, form and content of Notice of Appeal); 28 Pa. Code § 1230.39 (relating to timeliness of Notice of Appeal); 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 § 421.21 (relating to reconsideration of adverse determination and request for hearing); 52 Pa. Code § 3.111 (relating to form and content of informal complaints); 52 Pa. Code § 1003.41 (relating to form and content of informal complaints); 55 Pa. Code § 41.31 (relating to request for hearing); 55 Pa. Code § 41.32 (relating to timeliness and perfection of requests); 55 Pa. Code § 41.33 (relating to appeals nunc pro tunc); and 61 Pa. Code § 703.5 (relating to other submissions).