binaries in xml schema?

John Cowan cowan at
Wed Apr 21 19:46:55 BST 1999

xml wrote:

> Knowing that the data format will be used to store binaries anyway in
> embedded markets, I have to wonder if there is a formalized way to solve
> the problems in embedding binary in XML documents.  Because it is going to
> happen... there can't be any question about that.

Binaries will have to be encoded before being embedded, period.
Anything else isn't XML.  After all, what prevents the binary
from containing < or &, never mind any of the illegal characters
in the 00-1F range?
> I understand that a schema mechanism is being added to XML.  I don't know
> anything about it... haven't been able to find anything yet.  But, if a
> schema is available in the file with the XML datasets, several binary datatypes
> should be able to be called out.  This would make the MIME-happy folks happier
> and help us build xml-compliant consumer electronic blocks that are affordable.

Sure.  With or without schemas, you can tag elements as containing
base-64 encodings of any MIME type you want.  But there has to be
an encoding, not raw binary bits.

> So... is there any public information about XML-Schema?  Any idea if one or
> more binary formats is called out as a datatype within it?

You can read the various W3C Notes: XML-Data, DCD, SOX, DDML.
None of them tolerate raw binary.  Several provide a datatype
tag for base-64-encoded octets.

John Cowan		cowan at
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)

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