Yemen was admitted under now-obsolete rules of procedure. According to the United Nations Treaty Collection:

"The Provisional Rules of Procedure of the General Assembly (rules 113-116), under which the first six new Members were admitted to membership in the United Nations, namely, Afghanistan, Iceland, Pakistan, Sweden, Thailand and Yemen, stipulated that the membership, in case of a favourable decision of the General Assembly, shall become effective on the date on which the applicant State presented to the Secretary-General an instrument of adherence. Accordingly, the membership of Afghanistan, Iceland and Sweden became effective on 19 November 1946, that of Thailand on 16 December 1946 and that of Pakistan and Yemen on 30 September 1947.

By resolution 116 (II) of 21 November 1947, the General Assembly adopted new rules governing the admission of new Members. Under these rules (135-139), a declaration, made in a formal instrument accepting the obligations contained in the Charter, shall be submitted to the Secretary-General by an applicant State at the same time as the application for membership. The membership becomes effective, if the application is approved, on the date on which the General Assembly takes its decision on the application. Accordingly, for all Members other than the six mentioned in the preceding paragraph, the membership became effective on the respective dates of adoption as indicated in the third column of the table."