Mika Epstein notifies developers of a recent plugin guideline change in the WordPress plugin repo. Guideline 12 (“Public facing pages on WordPress.org may not spam”) is now more clear in broadcasting the message “Do not use your readme to spam.” This includes tags, keyword stuffing, and affiliate links.
Guideline 13 has been completely rewritten for security reasons: “…plugin should make use of WordPress’ default libraries.” Mika cites an example of plugin authors including the entire PHPMailer library, and not keeping it updated. A public page of 3rd part libraries is coming soon.