http://www.sos.state.co.us/CCR/Upload/NoticeOfRulemaking/AddInfoAttach2009-00531.PDF said:
Rule 81.1 — Statement of Purpose
The rules in this section have been adopted to contribute to the elimination of discrimination on the basis of sexual orientation, inclusive of transgender status, in employment, housing, public accommodations, and advertising, as required by Parts 3 to 7 of Article 34, Title 24, Colorado Revised Statutes, as amended, hereinafter referred to as the “Law.” C.R.S. §24-34-305(1)(a), entitled “Powers and Duties of Commission,” authorizes the Commission to “adopt, publish, amend and rescind” regulations consistent with and for the enforcement of the Law.
Rule 81.2 — Sexual Orientation Definitions
(A) The term “sexual orientation,” as defined in the Law, means a person’s orientation toward heterosexuality, homosexuality, bisexuality, transgender status or another person’s perception thereof.
(B) The term “transgender” means having a gender identity or gender expression that differs from societal expectations based on gender assigned at birth.
(C) The term “gender identity” means an innate sense of one’s own gender.
(D) The term “gender expression” means external appearance, characteristics or behaviors typically associated with a specific gender.
(E) The term “covered entity” means any person, business, or institution required to comply with the antidiscrimination provisions of the Law.
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Rule 81.11 — Gender-Segregated Facilities
(A) Nothing in the Act prohibits segregation of facilities on the basis of gender.
(B) All covered entities shall allow individuals the use of gender-segregated facilities that are consistent with their gender identity. Gender-segregated facilities include, but are not limited to, restrooms, locker rooms, dressing rooms, and dormitories.
(C) In gender-segregated facilities where undressing in the presence of others occurs, covered entities shall make reasonable accommodations to allow access consistent with an individual’s gender identity.