In brief, html or text based files are supposed to be transferred in ASCII mode.
Uploading them in Binary mode will append ^M's to the end of every line. In most
cases this is OK with html files, because your browser will ignore them. BUT, with other
text files such as cgi scripts, uploading them in binary will damage them, thus causing
a 'server 500 error'. This is because binary mode has added ^M's to the end of every
line, which are not supposed to be in the program. This of course, is what causes the
additional message of 'Malformed Headers', which often displays at the bottom of the
"Server 500" message when a cgi script has crashed.
BINARY mode is used for transferring executable programs, compressed files and all
image/picture files. If you try to upload an image in ASCII mode, you observer a strange
mess appearing on the page where the image is suppose to appear. ASCII mode in this
case, has corrupted the binary coding in the jpeg or gif image. If this happens, just
re-upload it in the Binary format.
