permalinks in documentation

There are instances where linking to "current" documentation is a bad idea. For example,

http://elasticsearch-users.115913.n3.nabble.com/What-is-the-meaning-of-throttle-time-in-millis-tp4050893p4050921.html

The post points to the link for [current documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules-store.html#store-throttling) which contains no info for store throttling, like the [1.7 version of the document](https://www.elastic.co/guide/en/elasticsearch/reference/1.7/index-modules-store.html#store-throttling).

Is there a way we can encourage the use of permalinks in our documentation to avoid this problem? Sometimes it is not obvious how to obtain the permalink in Elastic documentation; [Logstash Introduction](https://www.elastic.co/guide/en/logstash/current/introduction.html#introduction) is an example.

New documentation is comes with every release and we should try to encourage those linking to the docs to only use permalinks as those links run the risk of being invalidated.