37 CFR §11.704

1. (a)A practitioner may communicate the fact that the practitioner does or does not practice in particular fields of law.
2. (b)A registered practitioner under § 11.6(a) who is an attorney may use the designation “Patents,” “Patent Attorney,” “Patent Lawyer,” “Registered Patent Attorney,” or a substantially similar designation. A registered practitioner under § 11.6(b) who is not an attorney may use the designation “Patents,” “Patent Agent,” “Registered Patent Agent,” or a substantially similar designation. A registered practitioner under § 11.6(d) who is an attorney may use the designation “Design Patent Attorney.” A registered practitioner under § 11.6(d) who is not an attorney may use the designation “Design Patent Agent.” Unless authorized by § 11.14(b), a registered patent agent or design patent agent shall not hold themself out as being qualified or authorized to practice before the Office in trademark matters or before a court.
3. (c)[Reserved]
4. (d)A practitioner shall not state or imply that a practitioner is certified as a specialist in a particular field of law, unless:
   1. (1)The practitioner has been certified as a specialist by an organization that has been approved by an appropriate state authority or that has been accredited by the American Bar Association; and
   2. (2)The name of the certifying organization is clearly identified in the communication.
5. (e)Individuals granted limited recognition may use the designation “Limited Recognition” but may not hold themselves out as being registered.