Here on Meta, we have a faq tag.
It contains many topics that describe in high-quality detail how the SE network functions. By convention, we mark these posts Community Wiki and protect them. This lowers the bar for community contributions, but raises the bar for would be spammers.
I propose that we do the same for "Answer Your Own Question" posts on the main sites, automatically.
I have been interested for awhile in finding ways to encourage Canonical Posts. What is a canonical post? It is basically an answer to a frequently-asked question, the FAQ form of a Stack Exchange problem/solution. Canonical Posts are especially useful at Stack Overflow, which is heavily weighted towards very specific solutions to very specific problems. The purpose of SE is not only to answer people's questions, but to collect information that is useful to others. Canonical Posts can provide a venue for more general solutions, applicable to a wider audience.
For a perfect example of a canonical post, see here:
How can I prevent SQL injection in PHP?
Making these posts CW from the start would quell the most common objection to these posts, which is rep whoring. While I personally feel that users who take the time and effort to write such posts should be rewarded for it, writing good canonical questions and answers is hard, and I suspect that the ones who succeed at writing good Canonical Posts are more interested in getting the information out there in a well-written, easily consumable form than they are about rep gain. Perhaps a new badge that rewards well-curated canonical posts?
Setting Answer Your Own Question posts to CW, protecting them, and providing a badge for well-curated questions could be the Canonical Question platform that we've been looking for.