Of counsel is a reference to an attorney who participates on a case by case basis in the activities of a law firm. An of counsel position is not actively involved in the day-to-day work of a law firm, but may be available in particular matters or for consultation. "Of counsel" originally described a semi-retired or retired partner who still kept a hand in the firm. Putting the name of the attorney "of counsel" adds the prestige of the lawyer's name and reputation, without requiring his/her full-time presence.
There are four usual variants to the "of counsel" designation:
These four examples underscore that "of counsel" should not be used to designate more casual relationships which depend on the occasional consultation; the co-counseling of a single case, even if it is of long duration; "a relationship involving only occasional collaborative efforts among otherwise unrelated lawyers or firms"; or a relationship based solely on making or accepting referrals.