1. asc——非定界ascii文件，是一個ascii字符流。數據流中的行由行定界符分隔，而行中的每一列則通過起始和結束位置來定義。例如：
10 head Office 160 corporate new york
15 new england 50 eastern boston
20 mid atlantic 10 eastern washington
38 south atlantic 30 eastern atlanta
42 great lakes 100 midwest chicago
51 plains 140 midwest dallas
66 pacific 270 western san francisco
84 Mountain 290 western denver
2. del——定界ascii文件，也是一個ascii字符流。數據流中的行由行定界符分隔，行中的列值由列定界符分隔。文件類型修飾符可用於修改這些定界符的默認值。例如：
10,"head Office",160,"corporate","new york"
15,"new england",50,"eastern","boston"
20,"mid atlantic",10,"eastern","washington"
38,"south atlantic",30,"eastern","atlanta"
42,"great lakes",100,"midwest","chicago"
51,"plains",140,"midwest","dallas"
66,"pacific",270,"western","san francisco"
84,"Mountain",290,"western","denver"
