Z:gnu-www-ja-gpl-faq--697b2d-Consider HTTP as an example./en

Consider HTTP as an example. All HTTP clients expect servers to provide certain functionality: they should send specified responses to well-formed requests. The reverse is not true: servers cannot assume that the client will do anything in particular with the data they send. The client may be a web browser, an RSS reader, a spider, a network monitoring tool, or some special-purpose program. The server can make absolutely no assumptions about what the client will do&mdash;so there's no meaningful way for the server operator to be considered a user of that software.