With 8.1, the following attributes are updated:

`:ProductVersion: 8.1`
`:ProductPreviousVersion: 8.0`

Assess whether the ~13 links that use `ProductPreviousVersion`, under the "Book Links" section of `common/attributes.adoc`, need to continue to point to the `7.4` documentation.

For any link that needs to continue pointing to the `7.4` documentation, replace `ProductPreviousVersion` with `ProductPreviousPreviousRelease`.

":ProductPreviousPreviousRelease: 7.4"

An example is `:LinkDevelopmentGuide:`.