There are a set of questions that are a bad fit for Stack Exchange. Every site has a
/help/dont-ask page that describes what SE sites are looking for and what kinds of questions aren't a good fit for SE sites. Sometimes, the questions that aren't a good fit become very popular - they are shared and linked to on various sites around the Internet or otherwise generated a large number of views and answers. However, deletion may not be appropriate because they have useful content that should be preserved because it doesn't exist elsewhere or deletion may cause 404 errors to unregistered or low-reputation users coming from other sites. We could use better tools for managing these "bad", but very popular and useful questions.
Below are a number of suggestions to address this:
Change the text of the "historical lock" reason. Right now, this reason says that the lock exists for questions that have "historical significance". However, some questions can slip through the cracks for a small period of time (6 months - 1 year). To me, this isn't enough time to be "historically significant" to a site. The idea that this question is not a good question or an on-topic question is good (and links to the
/help/on-topicpages), but not the historical reason. This reason should reflect that the question and its answers add value to help make the Internet a better place.
Autogenerate moderator flags when popular questions are either closed or deleted by the community. Popular could be determined by a number of factors such as views on the question, votes on the questions, votes on the answers, number of answers, answer score, and/or average answer score.
An additional lock type that prevents deletion or reopening of a question, due to its value, but allows people to leave comments to note issues with the posts (possible reasons for commenting that would be valid: URLs that have gone dead and new URLs, revised information that makes part of an answer out-of-date, or links to related questions or postings on the site or other sites). It may be worth discussing other permissions that could still be granted, such as editing the question or answer, voting on the question and answers, or voting to delete low-quality answers. Per the comments, this could be a repurposing and update to the wiki answer lock reason. (Personally, I feel that repurposing the historical lock would be more appropriate).
What else can / should we be doing to balance the desire to close questions that aren't a good fit for a site and prevent people from using old, open and unlocked questions as evidence that they can ask their question, but also ensure that content lives on appropriately and is accessible to others, even if it's not the best match for the current definition of an SE site?