Editing JSON (section)

== Interoperability ==
RFC 8259 describes certain aspects of JSON syntax that, while legal per the specifications, can cause interoperability problems.

* Certain JSON implementations only accept JSON texts representing an object or an array. For interoperability, applications interchanging JSON should transmit messages that are objects or arrays.
* The specifications allow JSON objects that contain multiple members with the same name. The behavior of implementations processing objects with duplicate names is unpredictable. For interoperability, applications should avoid duplicate names when transmitting JSON objects.
* The specifications specifically say that the order of members in JSON objects is not significant. For interoperability, applications should avoid assigning meaning to member ordering even if the parsing software makes that ordering visible.
* While the specifications place no limits on the magnitude or precision of JSON number literals, the widely used JavaScript implementation stores them as IEEE754 "binary64" quantities. For interoperability, applications should avoid transmitting numbers that cannot be represented in this way, for example, 1E400 or 3.141592653589793238462643383279.
* While the specifications do not constrain the character encoding of the Unicode characters in a JSON text, the vast majority of implementations assume [[UTF-8]] encoding; for interoperability, applications should always and only encode JSON messages in UTF-8.
* The specifications do not forbid transmitting byte sequences that incorrectly represent Unicode characters. For interoperability, applications should transmit messages containing no such byte sequences.
* The specification does not constrain how applications go about comparing Unicode strings. For interoperability, applications should always perform such comparisons code unit by code unit.

In 2015, the IETF published RFC 7493, describing the "I-JSON Message Format", a restricted profile of JSON that constrains the syntax and processing of JSON to avoid, as much as possible, these interoperability issues.

=== Semantics ===
While JSON provides a syntactic framework for data interchange, unambiguous data interchange also requires agreement between producer and consumer on the semantics of specific use of the JSON syntax.<ref>{{harvnb|ref=ecma2017|ECMA-404, 2nd ed.|p=iii}}: "The JSON syntax is not a specification of a complete data interchange. Meaningful data interchange requires agreement between a producer and consumer on the semantics attached to a particular use of the JSON syntax. What JSON does provide is the syntactic framework to which such semantics can be attached"</ref> One example of where such an agreement is necessary is the serialization of data types that are not part of the JSON standard, for example, dates and [[regular expression]]s.