Ian Ford asked about support for the FTP command ACCT, and I discovered it is

present in RFC959... so now (lib)curl supports it as well. --ftp-account and
CURLOPT_FTP_ACCOUNT set the account string. (The server may ask for an account
string after PASS have been sent away. The client responds with "ACCT [account
string]".) Added test case 228 and 229 to verify the functionality. Updated
the test FTP server to support ACCT somewhat.

lib/urldata.h

@@ -862,6 +862,7 @@ struct UserDefined {
   char *cookiejar;      /* dump all cookies to this file */
   bool cookiesession;   /* new cookie session? */
   bool crlf;            /* convert crlf on ftp upload(?) */
+  char *ftp_account;    /* ftp account data */
   struct curl_slist *quote;     /* after connection is established */
   struct curl_slist *postquote; /* after the transfer */
   struct curl_slist *prequote; /* before the transfer, after type */