35 Ill. Adm. Code 166.275
Documentary Evidence
Section 166
Section 166.275 Documentary
Evidence
a) Relevant scientific or technical articles, treatises, or
materials may be introduced into evidence by stipulation of the parties, or
subject to qualification of the author and subject to refutation or disputation
through any introduction of comparable documentary evidence or expert
testimony.
b) Any writing or record made as a memorandum of any act,
transaction, occurrence or event shall be admissible as evidence of the act,
transaction, occurrence or event provided it was made in the regular course of
the business to make such a memorandum or record at the time of such an act,
transaction, occurrence or event or within a reasonable time thereafter.
c) All other circumstances of the making of the writing or
record, including lack of personal knowledge by the maker, may be shown to
affect its weight but shall not affect its admissibility.