Tacit knowledge is not equal to knowledge. Treating it as such leaves us with an impoverished notion of agency.
Tacit knowledge is knowledge which regulates activities but is not consciously possessed or expressed.
Tacit knowledge is practical ability or skill acquired through habituation. It is not knowledge 'as something gained and maintained by an intellectual faculty for abstract symbolic manipulation'.
Tacit knowledge is knowledge which exist in a practical state in an agent's practice and not in their consciousness or rather in their discourse.
Tacit knowledge is invoked to escape from the philosophy of the subject without doing away with the agent, and to escape from the philosophy of the structure but without forgetting to take into account the effects it wields on and through the agent.