Arguments of set command on memcached telnet (1)

On memcached telnet, set command has 4 arguments:

set some_key 0 0 1

Of course, 1st argument(e.g. some_key) is the key. But, what are rest of arguments?

2nd argument : flag

2nd argument(e.g. 0) is the flag. The flag is a 32bit integer value to determine how persist data into memcached. And let's check where flag appears on the telnet, use set, get and replace(same arguments with set).

set some_key 0 0 1
a
STORED
get some_key
VALUE some_key 0 1
a
END
replace some_key 1 0 1
b
STORED
get some_key
VALUE some_key 1 1
b
END

(continue to phosphorescence: Arguments of set command on memcached telnet (2))