Not sure if it can help you, but...: http://plugins.b2evolution.net/wiki-links

Hmm.. kind of but not really. The title is not the identity of the post i.e. if I correct a typo in the title all the links to it will have to be changed too. The identity is usually an identifier of some kind that is intrinsically linked to the post. It is usually the database id of the post because you can change every part of the post and any configuration option in the system but the post id will always be the post reference.

I'd have thought something like this would have been build into the core of the system and not be a plugin.

What you described is what I understood as permalinks in b2e:
http://b2evolution.net/man/permalink
http://b2evolution.net/man/single-post-pages-seo
http://b2evolution.net/man/appearance-of-my-permalinks
(:

WikiLinks will work because if you correct a typo you can still keep the old post slug in addition to the new one, so wikilinks will still know where to link to.

We will add a [[#123]] notation though.

That's a bit more like it. I always wondered what the point of permalinks were!

<a href="?p=123">Some title with potential mistakes</a>

But I still have to maintain the title. It's still not quite as automatic as #123 (or similar notation) that digs out the correct title and formats the link according to the current SEO configuration.

Maybe I'll have to invent my own render plugin to do this. :(

Sorry Francois didn't see your post until after my comment was submitted, thanks for adding the hash notation. I think it will help.

While the permalink/slug stuff kind of works I have found it a bit fiddly when correcting title spelling mistakes and then re-jig or delete erroneous slugs.