файлы дампа в различных форматах (dump files in various formats)
Использование в приложениях (Application usage)
XSI-conformant applications are warned not to use filenames
starting with '+' or a first operand starting with a numeric
character so that the old functionality can be maintained by
implementations, unless they specify one of the -A, -j, or -N
options. To guarantee that one of these filenames is always
interpreted as a filename, an application could always specify
the address base format with the -A option.