You may come across various discussions or documents marked as outdated or upon first going to that link you get a pop-up alerting you that it is outdated. The community manager only marks content as outdated based upon factual accuracy or relevance, as opposed to simply archiving content by how old it is because relevance can be subjective. For instance, a restaurant recommendation may be relevant for years on end, while a discussion about the 2009 MegaBonus may be relevant for up to a year.
For your convenience, outdated content is still available in the community. Just click on View this document [or discussion] anyway to go to it. Outdated content is not removed so you can reference these previous documents as you’d like.
If you use the search (magnifying glass icon in the upper right), outdated content that matches your keywords will appear in your farther down in the results.