Remarks: If you do not supply a target object at the command prompt, the target object is obtained from standard input (stdin). ...

Remarks:
If you do not supply a target object at the command prompt, the target
object is obtained from standard input (stdin). Stdin data can be
accepted from the keyboard, a redirected file, or as piped output from
another command. To mark the end of stdin data from the keyboard or
in a redirected file, use Control+Z, for End of File (EOF).

If a value that you supply contains spaces, use quotation marks 
around the text.

If you enter multiple values, the values must be separated by spaces
(for example, a list of site links).