Obviously the most reliable sources from whom to seek clarification are the persons who played key roles in drafting the resolution, British Ambassador to the UN, Lord Caradon, American Ambassador, Arthur Goldberg and US Undersecretary of State for Political Affairs, Eugene Rostow.
In an article in The New Republic, "Resolved: are the settlements legal? Israeli West Bank policies," (Oct. 21, 1991) Rostow wrote
"Five-and-a-half months of vehement public diplomacy in 1967 made it perfectly clear what the missing definite article in Resolution 242 means. Ingeniously drafted resolutions calling for withdrawals from 'all' the territories were defeated in the Security Council and the General Assembly. Speaker after speaker made it explicit that Israel was not to be forced back to the 'fragile and vulnerable' Armistice Demarcation Lines, but should retire once peace was made to what Resolution 242 called 'secure and recognized' boundaries, agreed to by the parties. In negotiating such agreements, the parties should take into account, among other factors, security considerations, access to the international waterways of the region, and, of course, their respective legal claims".
Goldberg has clarified that although the French and Soviet texts differ from the English in this respect, the Security Council voted on the English text, which is thus determinative. He Caradon and Rostow have stated categorically that in drafting resolution 242, they deliberately omitted a demand for Israel to return to the pre-1967 borders.
In an interview in the Beirut Daily Star on June 12, 1974, Caradon stated:
"It would have been wrong to demand that Israel return to its positions of June 4, 1967 because these positions were undesirable and artificial. After all, they were just the places where the soldiers on each side happened to be on the day the fighting stopped in 1948. They were just armistice lines. That's why we didn't demand that the Israelis return to them, and I think we were right not to."