学校要的SUPPORTING DOCS中有一条是 “Documentary proof of present and previous employment with designation, dates of appointment and resignation indicated (e.g. IR8A forms or letters of appointment and resignation). ” 这个我怎么出呢,是自己写段证明敲个公司章呢,还是拿劳动合同出来捏? 另外designation, dates of appointment and resignation indicated 是不是要拿辞职时候的退工单出来呀?职位这些又要怎么写呢