TABLE 17-1   FIRST-DIGIT FTP REPLY CODES
First Digit	Category Description
1xx	“Okay so far, I’ll get back to you in a second.”
2xx	“All done, everything went well.”
3xx	“I got that part, but I still need more information from you.”
4xx	“I can’t do that now, try again later.”
5xx	“Sorry, Dave, I can’t do that.”