外封 meaning in English

covering

Fibre optic enclosures - generic specification
光纤外封壳体.总规范
External casing packer
套管外封隔器
Copper and copper alloys - pre - insulated copper tubes with solid covering ; german version en 13349 : 2002
铜和铜合金.坚固体外封预绝缘铜管
Further , as the runtime marshals data in and out of a type , the data might be copied or transformed
此外，当运行库在类型中和类型外封送数据时，可能会复制或转换数据。