Consider always using the versioned URL (even when latest GA)

[rwinch]

Indexing of search uses the URL that it finds. This works well except when we index the current version and then do a release where the current version changes. In this case, the search results for the old current version will point to the new current version. We might be able to improve this by always having the generation in the URL for the indexed page.

The downside of this is that a search on the current revision will always link to a versioned URL which results in a redirect. The impact of this is a lot more frequent than the day after a new GA is released getting links to the new GA from a search on the old GA so we should consider this carefully before implementing it.