Last call for consensus on format-control char. issues

Douglas Crockford douglas at
Wed Jun 17 13:01:21 PDT 2009

John Cowan wrote:
> David-Sarah proposes treating BOM in an identifier, string literal,
> or other token as an error, since the intent is unclear (non-initial
> BOMs shouldn't appear in properly formatted text any more, now that the
> "zero-width separator" semantics has been taken over by U+2060 WORD
> JOINER), and ignoring all other instances of BOM.  That seems like TRT
> to me.

The reality is that BOM is placed at the top of .js files by some text editors 
and that .js files get concatenated together to improve page startup times. The 
reality is that BOM in that context is whitespace.

As far as I am aware, there is no other use of BOM in JavaScript program text. 
Treating BOM as an error has already been proven to cause misery in the world. 
Treating BOM as whitespace will reduce misery. I wish we could claim that it 
will end all human misery, but at least we will be trending in the right direction.

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