It seems as if we are at the beginning of an age in which many more internet accessible data will be coupled. While this is an exiting development that may add a lot of value to resources. It will only succeed only if we follow sound principles. The main danger is the propagation of errors because the same data are included in different settings.

Inclusion is not neutral. It may imply appropriation of material that is created by someone else. But it also gives a stamp of approval to the data included. The new resource may again be included in other mashups or compilations. This makes the principal source invisible. It is often inevitable to combine sources of mixed reliability, if only because they are the only resources available or accessible.

Jon Udell has written some guidelines:

1. Be the authoritative source for your own data

2. Pass by reference not by value

3. Know the difference between structured and unstructured data

4. Create and adopt disciplined naming conventions

5. Push your data to the widest appropriate scope

6. Participate in pub/sub networks as both a publisher and a subscriber

7. Reuse components and services