Ill. Admin. Code tit. 77, § 949.30
a) Any person may register a complaint with the Department, a State-certified local public health department, or a local law enforcement agency for a violation of the Act or this Part. (Section 40(b) of the Act) Complaints shall be registered with the Department by calling the following toll-free telephone number: 1-866-973-4646 or by registering a complaint or downloading a complaint form from the Department's website (www.dph.illinois.gov). A complaint registered with the Department, a State-certified local public health department, or a local law enforcement agency shall include:
3) A description of the occurrence that prompted the complaint; and
d) After the receipt of a complaint, a State-certified local public health department or a local law enforcement agency shall investigate the complaint in accordance with the local health department's Smoke-Free Illinois enforcement policy on file with Department by:
e) In determining whether a violation of the Act or this Part has occurred, the Department, State-certified local public health department, or local law enforcement agency shall consider the following:
3) The presence of smoke or smoking;