As used in this chapter, the terms "business entity" and "collaboration" include employer and employee relationships, joint ventures, partnerships, general corporations, and consulting relationships formed by written agreement in which the architect provides immediate and responsible direction of architectural services. For purposes of this section, "immediate and responsible direction" has the same meaning as that term is defined in Section 151 of Title 16 of the California Code of Regulations.
Ca. Bus. and Prof'l. Code § 5535.25