$zcvt("abc/def","O","JSON")="abc/def" -> Why?

The quoting of the slash character, "/", is optional in JSON.  When doing a $ZCVT output conversion ,"O", in JSON IRIS chooses to not quote the slash character.  It makes the output easier to read.  However, $ZCVT doing an input conversion, "I", will recognize a quoted slash character in JSON input.  E.g.:

USER>w $zcvt("abc\/def","I","JSON")
abc/def
USER>w $zcvt("abc/def","I","JSON") 
abc/def