In Eastern Orthodoxy, akribia is strict adherence to the letter of the law of the church, as distinguished from economy, which is discretionary deviation from the letter of the law in order to adhere to the spirit of the law.

Only bishops have such discretion, which may be used on the occasion of a conversion to Orthodoxy, in order to grant recognition to a baptism previously administered in a heterodox or schismatic church. It may also be used to grant recognition to an ordination administered in a Roman Catholic or Anglican church if the convert comes from either of those communions.