1) Ratification : a treaty is generally open for signature for a certain time following the conference which has adopted it. However, a signature is not binding on a State unless it has been endorsed by ratification. The time limits having elapsed, the Conventions and the Protocols are no longer open for signature. The States which have not signed them may at any time accede or, in the appropriate circumstances, succeed to them.
Accession : instead of signing and then ratifying a treaty, a State may become party to it by the single act called accession.
2) Reservation / Declaration : unilateral statement, however phrased or named, made by a State when ratifying, acceding or succeeding to a treaty, whereby it purports to exclude or to modify the legal effect of certain provisions of the treaty in their application to that State (provided that such reservations are not incompatible with the object and purpose of the treaty).
Palestine : On 21 June 1989, the Swiss Federal Department of Foreign Affairs received a letter from the Permanent Observer of Palestine to the United Nations Office at Geneva informing the Swiss Federal Council "that the Executive Committee of the Palestine Liberation Organization, entrusted with the functions of the Government of the State of Palestine by decision of the Palestine National Council, decided, on 4 May 1989, to adhere to the Four Geneva Conventions of 12 August 1949 and the two Protocols additional thereto".
On 13 September 1989, the Swiss Federal Council informed the States that it was not in a position to decide whether the letter constituted an instrument of accession, "due to the uncertainty within the international community as to the existence or non-existence of a State of Palestine".
Niue : Geneva Conventions 1949 : As evidenced by paragraph 10(1) read together with sub-paragraph 10(3)(b) of New Zealand's 1958 Geneva Conventions Act adopted in anticipation of New Zealand's accessions (2 May 1959) to the Four Geneva Conventions of 1949, Niue's Geneva Conventions Act 1958 (published most recently in Niue Laws 2006, vol. 2, p. 877), bearing in mind the rule as expressed in Article 29 of the 1969 Vienna Convention on the Law of Treaties, and following discussions with relevant authorities, the International Committee of the Red Cross considers that the 1959 New Zealand accessions cover the territory of Niue.