From Language Log:
According to Worldpress.org, the United Nations Secretariat has issued two editorial directives insisting on usage of "the Persian Gulf" rather than "the Arabian Gulf" or simply "the Gulf." An addendum to one directive reads, "The full name 'Persian Gulf' should be used in every case instead of the shorter term 'Gulf,' including in repetitions of the term after its initial use in a text." So from the U.N. Secretariat's point of view, use of "(the) Gulf" is off-limits in any circumstances (even after using "Persian Gulf" on first reference). Rather than wading into this minefield, I'd suggest Language Log adopt its own editorial directive. From now on, we should only refer to "The Large Body of Water between the Arvandrud/Shatt al-Arab River Delta and the Straits of Hormuz."That'll show 'em!