The subject field of the message is ignored. Each message is a request to the service. Each request consists of a number of commands. Each command must start with a new line with no leading spaces. Continuation lines begin with a space or a tab.
All commands are case-insensitive.
Requests are associated with the return address of the user message. Service replies and deliveries will be sent to that address. The usages of the commands are as follows. Subscribe for articles relevant to the profile specified by 's. The most relevant article is given a score of 100.