How does the Xref: field in news articles work?

[Dave Taylor]

	I have noticed that articles that are cross-posted (ie posted
to more than one group) have a line of the form;

Xref: 4454 343 898

at the top.

	How does one interpret this?  Is it as it seems, they apply to
the specified groups IN ORDER as presented in the 'Newsgroup:' line?

(that is, if the file contained;

Newsgroup: net.apple, net.orange, net.fruit-cakes
...
Xref: 340  4564 45

it would refer to net.apple article #340, net.orange article #4564 and
net.fruit-cakes article #45?)

	Thanks for any confirming/denying information!

				Dave Taylor