35 Ill. Adm. Code 130.302
Owner's Responsibility to Mark Article
Section 130
Section 130.302 Owner's
Responsibility to Mark Article
a) When an entire article is claimed to represent a trade secret,
the owner must mark the article with the words "Trade Secret" in red
ink on the face or front of the article.
b) When less than an entire article is claimed to represent a
trade secret, the owner must:
1) Mark the article with the words "Trade Secret" in
red ink on the face or front of the article;
2) Indicate on the face or front of the article which page or
portion of the article is claimed to represent a trade secret;
3) Mark every page or portion of the article that is claimed to
represent a trade secret with the words "Trade Secret"; and
4) Furnish the State agency with a second copy of the article
from which the page or portion of the article that is claimed to represent a
trade secret is deleted.