RFC 7159, "The JavaScript Object Notation (JSON) Data Interchange Format", March 2014

Note: This RFC has been obsoleted by RFC 8259

Errata ID: 3983
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
Reported By: Alain BENEDETTI
Date Reported: 2014-05-09
Rejected by: Pete Resnick
Date Rejected: 2014-05-16

Section 2. says:

JSON-text = ws value ws

It should say:

JSON-text = [BOM] ws value ws

BOM = %xFEFF

Notes:

Section 8.1 states:
[START QUOTE]
(...) implementations that parse JSON texts *MAY* ignore the presence of a byte order mark rather than treating it as an error.
[END QUOTE]

Indeed that means that a BOM *CAN* occur, and *MAY* be accepted instead of returning an error. So, if the BOM can be accepted, the grammar is incomplete as it does not show it.

Furthermore, about BOMs, see my other comments.
--VERIFIER NOTES--
The WG was clear that syntactically, the BOM is not part of a valid JSON-text, but implementation advice included that if one appears, it MAY be ignored. The document is correct as-is.

Report New Errata