2. The link decoration approach
The approach assumes that, when linking to a web resource, a snapshot of the state of that resource
is created, for example, in a web archive or a versioning system.
Several web archives
provide services that allow
taking such snapshots, and versioning systems take them automatically. With a snapshot taken, a link can be made
more robust by including:
- The URI of the original resource for which the snapshot was taken;
- The URI of the snapshot;
- The datetime of linking, of taking the snapshot.
This information, when provided in a machine-actionable manner, allows:
- Visiting the snapshot;
- Revisiting the original resource some time after linking;
- Finding snapshots that are temporally close the one taken
in case the snapshot itself becomes temporally or permanently inaccessible.
The approach proposed here is to convey this information on a link by leveraging
. It introduces the following
data-originalurl for the URI of the original resource;
data-versionurl for the URI of the snapshot if one was taken;
data-versiondate for the datetime of linking, of taking the snapshot.
The remainder of this document details how to use these attributes for various cases.