They were removed because people started trying to use them to hold additional parsing directives and other meta-information which would have destroyed interope

They were removed because people started trying to use them to hold additional parsing directives and other meta-information which would have destroyed interoperability and defeated the entire purpose of a simple interchange format. See: https://groups.yahoo.com/neo/groups/json/conversations/topics/156 https://groups.yahoo.com/neo/groups/json/conversations/topic... If you want to annotate JSON in documentation, I say "go ahead and just use //". Any programmer reading it will understand that those lines are taken to be comments and they shouldn't type them in their final request.