The method of moving.
This field specifies the location in the file at which the read/write pointer
starts before adding the ib offset. The values and their meanings
are as shown in the following list:
- FILE_BEGIN
Move the pointer from the beginning of the file.
- FILE_CURRENT
Move the pointer from the current location of the read/write pointer.
- FILE_END
Move the pointer from the end of the file. Use this method to determine
a file's size.