1 [this validator](https://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fanarc.at%2Ftag%2Fdrupal-planet%2Findex.rss) says that my RSS feed doesn't validate.
3 the link to "comments" should be a full URL and there's a "self" tag missing.
5 coming from [this bug report](https://www.drupal.org/node/1843576)