Ill. Admin. Code tit. 77, § 340.1810
a) No later than the time of admission, the facility shall enter the following information, as applicable, onto the identification or admission sheet for each resident.
b) In addition to the information that is specified above, each resident's medical record shall contain the following:
4) An ongoing record of notations describing significant observations or developments regarding each resident's condition and response to treatments and programs.