Binary vs Ascii files - Unix uses different signals for the end of a line of text than Windows or Macintosh. This instructs the FTP server to correctly convert the carriage return signals between formats when uploading or downloading ASCII text files. HTML Files [.html, .html], Perl/CGI Files [.pl, .cgi], [php files .php] [database .sql] and Text files [.txt] should all be transferred using ASCII modes.

Any non-text files such as image foramts should be transferred Binary. Many FTP programs recognise these file types and will transfer them in the correct mode if set to automatic transfer.