| 110 | Restart marker reply. In this case, the text is exact and not left to the particular implementation; it must read: MARK yyyy = mmmm Where yyyy is User-process data stream marker, and mmmm server's equivalent marker (note the spaces between markers and "=").  | 
| 120 | Service ready in nnn minutes. | 
| 125 | Data connection already open; transfer starting. | 
| 150 | File status okay; about to open data connection. | 
| 200 | Command okay. | 
| 202 | Command not implemented, superfluous at this site. | 
| 211 | System status, or system help reply. | 
| 212 | Directory status. | 
| 213 | File status. | 
| 214 | Help message. On how to use the server or the meaning of a particular non-standard command. This reply is useful only to the human user.  | 
| 215 | NAME system type. Where NAME is an official system name from the list in the Assigned Numbers document.  | 
| 220 | Service ready for new user. | 
| 221 | Service closing control connection. Logged out if appropriate.  | 
| 225 | Data connection open; no transfer in progress. | 
| 226 | Closing data connection. Requested file action successful (for example, file transfer or file abort).  | 
| 227 | Entering Passive Mode (h1, h2, h3, h4, p1, p2). | 
| 230 | User logged in, proceed. | 
| 250 | Requested file action okay, completed. | 
| 257 | "PATHNAME" created. | 
| 331 | User name okay, need password. | 
| 332 | Need account for login. | 
| 350 | Requested file action pending further information. | 
| 421 | Service not available, closing control connection. This may be a reply to any command if the service knows it must shut down.  | 
| 425 | Can't open data connection. | 
| 426 | Connection closed; transfer aborted. | 
| 450 | Requested file action not taken. File unavailable (e.g., file busy).  | 
| 451 | Requested action aborted: local error in processing. | 
| 452 | Requested action not taken. Insufficient storage space in system.  | 
| 500 | Syntax error, command unrecognized. This may include errors such as command line too long.  | 
| 501 | Syntax error in parameters or arguments. | 
| 502 | Command not implemented. | 
| 503 | Bad sequence of commands. | 
| 504 | Command not implemented for that parameter. | 
| 530 | Not logged in. | 
| 532 | Need account for storing files. | 
| 550 | Requested action not taken. File unavailable (e.g., file not found, no access).  | 
| 551 | Requested action aborted: page type unknown. | 
| 552 | Requested file action aborted. Exceeded storage allocation (for current directory or dataset).  | 
| 553 | Requested action not taken. File name not allowed.  |