42 USC §2000e-3 | Other Unlawful Employment Practices
"(a) Discrimination for making charges, testifying, assisting, or participating in enforcement proceedings. It shall be an unlawful employment practice for an employer to discriminate against any of his employees or applicants for employment, for an employment agency, or joint labor-management committee controlling apprenticeship or other training or retraining, including on-the-job training programs, to discriminate against any individual, or for a labor organization to discriminate against any member thereof or applicant for membership, because he has opposed any practice made an unlawful employment practice by this subchapter, or because he has made a charge, testified, assisted, or participated in any manner in an investigation, proceeding, or hearing under this subchapter."
The judiciary takes the above statute to mean a prohibition against retaliation (for complaining about discrimination/harassment).
There are two main pillars of protection against retaliation.
The first is the opposition clause; which protects you when you file an internal complaint (ie, a complaint within your company/organization).
The second is the participation clause; which means that you filed an external complaint (ie, a complaint with a government agency (eg, EEOC, FCHR, etc.))
You should now have a better understanding for how your judge will construe the two clauses (opposition vs participation) from the federal law against employment retaliation.