The nature of Revocation and it's distinction from similar concepts

Revocation is one of the important legal institutions that beside institutions like right of option, and right to rescind allow people that by means of that cancel their previous actions and revoke of them. Revocation has an important role in adopting legal relationships of people in the society but in spite of this in the legal system of Iran no more attention is paid to it and the nature of it partially unknown and this matter cause an important question in this ground like that: what is the legal nature of legal institution of revocation? What is difference of revocation with other legal institutions such as right of option in the binding contract, and right to rescind in the revocable contract, cancellation (Eqaleh) and annulment (Enfesakh)? Is revocation a legal right (haq) and whetherit is relinquishable and transferableor it’s a legal ruling (hokm) and unrelinguishable and untransferable?
There is a disagreement between Foqaha and law makers About the nature and the effects of revocation .but what we achieved in this matter by study and analysis from the religious and legal sources is that in the perspective of legal nature Revocation is a juridical act and application and execution of it accomplish by the intention of revocation and revocation is one of the main evidences of unilateral act (Ighah) and materialized by an attention. Revocation has specific characterictis that mak it different from other legal institutions such as the right to option in the binding contract, right to rescind in the revocable contract, cancellation (Eqaleh) and annulment (Enfesakh). In addition itseems that revocation belongs to the legal rights (haq) that is relinquishable but untransferable.