INPUT
	TYPE	Any

OUTPUT
	TYPE	Any
	DESC	Filtered or decorated according to arguments

ARGUMENT
	MARK
		DESC	Add "MARK" flag
	FOR
		FORMAT	Filter

EXAMPLE
	#pass through packets queue
	> echo -n abc | bsdconv 'ascii:pass|pass:bsdconv-stdout'
	0161 ( SKIP )
	0162 ( SKIP )
	0163 ( SKIP )
	> echo -n 測試 | bsdconv 'utf-8:utf-16le|pass:bsdconv-stdout'
	2C6E ( FREE )
	668A ( FREE )
