“Ratification” and “signature” are both different names for the process whereby a state indicates to the other contraction parties its consent to be bound by the adopted international agreement. But still there is a difference between both terms.
“Signature” is a process that has different legal meanings depending on the circumstances in which it is performed. A distinction is made between “simple signature”, which is subject to ratification, and “definitive signature”, which is not subject to ratification.
The “simple signature” applies to most multilateral treaties. This means that when a State signs the treaty, the signature is subject to ratification, acceptance or approval. The State has not expressed its consent to be bound by the treaty until it ratifies, accepts or approves it. In that case, a State that signs a treaty is obliged to refrain, in good faith, from acts that would defeat the object and purpose of the treaty. Signature alone does not impose on the State obligations under the treaty. For states this usually means that the international agreement has to be put before the national parliament for approval, thereby giving the people a direct say in the external activities of the state.
The “definitive signature”, in contrary, occurs where a State expresses its consent to be bound by a treaty by signing the treaty without the need for ratification, acceptance or approval. A State may definitively sign a treaty only when the treaty so permits. To make the comparison: a definitive signature has the same force as a simple signature, which is followed by ratification.
Although this last process is becoming more common in international relations, the more commonly used procedure is still signature followed by ratification at a later stage.
Because of the fact that the Convention does not contain a provision stipulating the possibility of a definitively sign, signing the Convention only causes the effects of a simple signature. Thereby, ratification after a signature is necessary for a State to be bound to it.
“Ratification” in contrary to “signature” refers to the act undertaken in the international plane, whereby a State establishes its consent to be bound by a treaty. Usually ratification involves two distinct procedural acts. The first is related to the constitutional (internal) laws of a contracting party. It involves the international procedure that must be fulfilled before the state can assume the international obligations enshrined in the international agreement. In many instances this involves approval by the national parliament. The second element deals with the external (international) level. It is the process through which the contracting party indicates its consent to be bound to the other contracting parties.
Historically, ratification was intended to avoid that the representative exceeded his powers or instructions with regard to the making of a particular agreement. With the decline of absolute sovereigns and the increase of parliamentary democracies the consent by ratification has acquired a new meaning. Although it still gives the contracting parties the chance to weigh and consider their options under the proposed agreement, its most important role is to give the national parliament, and therefore the citizens, a direct sat in the public affairs of the state.
To summarize this topic, the countries which only signed, but not ratified the Convention have for the moment only an obligation to refrain, in good faith, from acts that would defeat the object and purpose of the treaty. Ratification stays necessary before the Convention becomes part of the legal system of those countries.