Also of note in the Mideast...

* Reliable Lebanese sources have so far been unable to substantiate Israeli allegations that the Lebanese Army was responsible for the disappearance of 1, 200 Palestinians. The charges, first made in the Israeli daily Maariv and still insisted upon by Israeli sources, also blamed the Lebanese Army for the destruction of numerous houses during its sweeps through Beirut's Palestinian camps last month.

With population displacement and destruction caused by the Israeli invasion, Red Cross officials say, it is virtually impossible to account for the whereabouts of all refugees. One Lebanese source contends the Israeli charges are designed to blacken the Lebanese government's image in the eyes of Palestinians. Even Palestine Liberation Organization officials are suspicious, although the PLO news agency, WAFA, expressed concern Nov. 27 that the Lebanese Army had ''stormed'' into Sabra, Shatila, and Borj el Barajneh camps recently.

* Though there is growing evidence of a split between the Syrian and non-Syrian wings of the PLO, the organization itself is trying to maintain its balance in its public statements. This is being done by means of veiled criticism of both wings. The Nov. 27 issue of the PLO magazine, Falestine Al-Thawra, complained that all Arab regimes are trying to limit movement of guerrillas, confiscating PLO arms, and ''trying to obliterate their revolutionary identity.'' Without mentioning them by name, Jordan was implicitly attacked for trying to ''confiscate the independence of Palestinian political decisions'' and Syria for ''stealing the slogans of the revolution,'' and issuing forged PLO communiques.