Likewise, how about about linking from and ead document to another ead
document or linking to a specific URL?
Judging from the retrospective conversion guidelines
(http://sunsite.berkeley.edu/amher/upguide.html) here's my thought:

<ENTITY dukew PUBLIC "-//Duke University::Special Collections
Library//TEXT(US::NcD::::Washington Duke Papers)//EN" "dukew.sgm">

See the <extref entityref="dukew">Washington Duke Papers</extref>

The delivery mechanism (Panorama, Dynaweb, etc.) could then use this to
link to the dukew.sgm file.
It does seem that either extref or extptr could be used with the same
effect.  Is one preferable over the other?

Linking to a specific url seems more complicated - while would be nice to
be able to do something like

See <extref href="http://www.domain.edu/copyrightinfo.html">Copyright
Information</extref>

but it seems to defeat the modularity of using an FPI - you'd have to
change all your sgml files if the url ever changed.
How have others gone about this?

Stephen Miller
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