The copies of The Bro Code featured in this episode are actual copies of the real book published in 2008.
Barney's suit is Moods Of Norway
Robin states her metabolism means she loses weight rather than gains it, which is similar to Lily needing to gain five pounds in order to fit into her wedding dress in the season 2 episode 'Showdown' because she kept losing weight accidentally. However whereas Robin was annoyed at Lily for that, Lily is annoyed at Robin because of this. (This is either ignored by Lily as her weight loss was due to wedding stress, not her metabolism like Robin's or they forget about Lily's similar weight loss).