S Sequential input mode is used for pipes and other sequential devices such as hardware ports. I record-length specifies the logical record length of the file. To use the existing record length for the file, specify a length of 0, or do not provide a value here. To use the existing record format, do not specify a value here. D use default record format.
E use editable record format.
F file contains fixed length records. P file contains printer carriage control in host-dependent record format. V file contains variable length records. Opening an existing file for output overwrites the current contents of the file without warning. You must associate a fileref with the external file before calling the F OPEN function.