Everyone missed the most *obvious* example of $encode.. to encode data using MIME/UUencode encoding.
Web/mail servers often require that certain headers or data is sent as base64 encoded data. base64 is just another name for MIME encoding.
When you send Basic Auth
information to a webserver, you're doing so with base64. It looks like this:
sockwrite -tn $sockname Authorization: Basic $encode(user:pass,m)
Other parts of HTTP require base64 as well. This seems like reason enough to me.