Alternate source tags?

Jim Taylor (
Mon, 29 Apr 1996 18:50:37 -0800

Message-Id: <>
Date: Mon, 29 Apr 1996 18:50:37 -0800
From: Jim Taylor <>
Subject:  Alternate source tags?

There's a trend towards supplementing Internet-based HTML content
with local (CD-ROM, hard disk, LAN) HTML content. I'm sure this trend
will continue to grow until Internet bandwith limits are no longer a
concern. I also hear rumors that Netscape Navigator 4.0 will somehow
support CD-ROMs.

In light of this, and before Netscape invents its own half-baked scheme,
perhaps this is a topic worthy of discussion in this group (unless it's
already been covered and I missed it :-).

It would be nice if there were a mechanism for specifying secondary
sources anywhere a SRC or HREF attribute can appear, something like

For example, if I create a huge set of content (hundreds of megabytes), I
would like someone to be able to download small parts of it (the parts
that change often) from the Internet but access the rest of it from a
CD-ROM. Essentially, the browser would look at the primary source first
(the Internet), and if it failed to find it there it would then look at the
secondary source (the CD-ROM). So most or all the content would start
out on the CD-ROM, but as things were changed they would come from
the Internet. Alternately, with a bandwith-conservation goal, the CD-ROM
could be the primary source so that users with the CD-ROM would get
things quickly and anyone else would wait for things to come slowly
over the Internet.

It would be useful if the spec allowed multiple alternate sources (look
here, then here, then here...) and also allowed date-ranked sources so
the browser would check all specified sources and then retrieve the
most recent one. 

This could tie in with new "predownloading" software.

Obviously it could impact performance, but those who value
performance can ignore the feature. It would have great benefits for
those of us who want to take advantage of HTML to deliver timely
content online that's integrated with large amounts of fast local
multimedia content.

Jim "The Frog" Taylor, Director of Information Technology
Videodiscovery, Inc. - Multimedia Education for Science and Math
Seattle, WA, 206-285-5400 <>