Why publish any usage guidelines at all?
Because as we’ve previously discussed, the Mozilla Foundation felt it was important that the icon mean something to people, particularly to end users who are just getting acquainted with the whole concept of web syndication and might see the icon as a relatively reliable guide by which to discover web feeds and ways to manipulate them. Taking a totally laissez faire approach might cause those users’ expectations to be completely violated, for example by frequently encountering information in web syndication formats that were proprietary and could not be processed by most feed-enabled applications.
Because as we’ve previously discussed, we felt it was important that the icon “mean something” to people, particularly to end users who are just getting acquainted with the whole concept of web syndication and might see the icon as a relatively reliable guide by which to discover web feeds and ways to manipulate them. Taking a totally laissez faire approach might cause those users’ expectations to be completely violated, for example by frequently encountering information in web syndication formats that were proprietary and could not be processed by most feed-enabled applications.