World Notes SOUTH AFRICA

Thirty years ago, Oliver Tambo slipped out of South Africa to establish an overseas network of the African National Congress just before the underground movement was crushed at home. Tambo, president of the A.N.C. since 1967, returned last week, flying into Johannesburg's Jan Smuts Airport to delirious shouts of "Tambo, Tambo, Tambo!"

Though he suffered a stroke 16 months ago, he was able to give the opening address at the first A.N.C. conference held inside South Africa in three decades. He surprised many delegates by calling for a re-evaluation of economic sanctions against Pretoria. "It is no longer enough," he said, "to repeat trite slogans." The A.N.C. leadership decided otherwise. The next day the conference unanimously passed a resolution rejecting any change in its sanctions policy.