Definitions for "Entry into force"
Multilateral agreements are usually not legally binding until they have been ratified by a certain number of countries. The UNCCD required 50 ratifications and entered into force on 26 December 1996. Equally the Convention states, that it will enter into force for a given Party 90 days after this Party has deposited its instrument of Ratification or Accession.
The treaty comes into force when a sufficient number of States have expressed their consent to be bound by the treaty. Then, the treaty has a legal existence in the international legal system and in the legal systems of States Parties.
Protocols and amendments are not legally binding until they have been ratified by an agreed number of countries; the Climate Change Convention required 50 and enters into force for each new Party 90 days after it ratifies.