There are many forms of prohibited employment discrimination. In general, each of these anti-discrimination provisions are reinforced by anti-retaliation provisions.
Although each anti-discrimination statue's provisions are slightly different, at a minimum, they provide protection to employees who "oppose" discrimination and/or "participate" in a proceeding related to a complaint of discrimination (such as filing an EEOC charge or lawsuit).
In many instances, even where a court or jury declines to find that an employer discriminated against an employee, they will still find for the employee regarding to a claim of retaliation. This is in large part because the standard for proving retaliation is often lower than proving the initial discrimination. Importantly, the New York City Human Rights Law's anti-retaliation provision has been described by courts as one of the most protective in the country.