The RSS 1.1: RDF Site Summary (DRAFT) contains a passage that I only noticed today ( through this posting). This fits well with the topic of developer arrogance. Because here again a developer has easily strayed from the path of reason. Of course, it's important that a standard is cleanly defined and that producers of formats adhere to these standards. It's also okay to require that a consumer of this format checks it and provides messages when deviations occur (though few users can make sense of their aggregator's messages anyway). But it's completely unrealistic to believe that aggregator users are satisfied when their aggregator just spits out an error message and no content. That's just as stupid as the same approach with XHTML - where some browsers actually implement it and don't go into Quirks Mode for broken XHTML, but simply deliver the XML parser error. Sorry, but that's complete nonsense. Every communication protocol has two ends - the producer and the consumer. And Postal's Law - be conservative in what you produce and liberal in what you accept - is simply the most sensible way to approach such communication protocols that transport content intended for humans. Requiring that consumer applications not display existing content due to format errors is simply unrealistic.