It means 'Shadowhunters: Looking Better in Black Than the Widows of our Enemies Since 1234'.
Cassandra ClareI think of myself as a freewheeling bisexual," added Magnus. "Please never say those words in front of my parents," said Alec.
Cassandra ClareHey, pretty thing," he said. "What's in the bag?" "Holy water," said Jace, reappearing beside her as if he'd been conjured up like a genie. A sarcastic blond genie with a bad attitude. "Oooh, a Shadowhunter," said the vampire. "Scary." With a wink he melted back into the crowd. "Vampires are such prima donnas," Magnus sighed from the doorway. "Honestly, I don't know why I have these parties." "Because of your cat," Clary reminded him. Magnus perked up. "That's true. Chairman Meow deserves my every effort.
Cassandra Clare