How to use binary data with XML?

John Cowan cowan at
Tue Apr 20 21:09:22 BST 1999

Roger L. Costello wrote:

> (1)  Binary data isn't actually put in an XML file, correct? i.e., the
> binary data is _not_ inline, correct?  An XML file just contains ASCII
> text, correct?

Correct in essence.  However, for "ASCII" read "characters,
expressed in Unicode or some subset of it".  Of course, ASCII
*is* a subset of Unicode.

> (2)  Just like in HTML, binary data is _referenced_ by the XML document,
> correct?

Typically.  Nothing prohibits you from encoding binary data as
Base64 and incorporating it into an XML document, but nobody has
converters for that yet either.
> (3) Is this the correct way of using binary data:

[example snipped]

> Here we see an XML document _referencing_ a file containg binary data.
> The binary data is not actually inline.  Is this how it's done?  

That is the fully standards-compliant way.  Application conventions
such as XLink (when it stabilizes) can simplify this process
by allowing in-line URIs and letting the network infrastructure
provide the remote document-type.

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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