Houston mayor Annise Parker issued an executive order banning discrimination against LGBT city employees. According to The Dallas Voice, the policy may be the most comprehensive in the nation.

The sweeping order, which was signed March 25 and took effect immediately, includes gender identity and gender expression protections. It enforces the policy among contractors, vendors, and city agencies.

The order makes it a violation “to fail or refuse to hire, recruit, appoint, promote or train any individual” based on sexual orientation or gender identity. It’s also a violation “to discipline, demote, transfer, lay off, fail to recall or terminate” or to “or to limit, segregate or classify employees or applicants” for those reasons.

Her order replaces one signed by Bill White, the former mayor who is running for the Democratic nomination for Texas governor.