I received a notification for a comment made by Emilio Pisanty on this question asking for an update of my answer in order to comply with the current policy on resource recommendations.
As you can verify, I wasn't the only one who received the same comment. I was wondering if it is wise to try to enforce a current policy on very old contributions. I feel it is too much to ask for a huge amount of users. Maybe this is our online version of retroactivity in law.