In the last two parts (Part 1 and Part 2) of using WordPress and the .html extension in permalinks, I’ve outlined the pros and the cons. Well, after a lot of testing, I’ve found a reason why you should probably avoid it.
When adding .html to the end of permalinks, the post slug behavior is changed. For some reason, WordPress’s slug engine now considers . to be an acceptable character for use in the URL text of an article.
So, when you say write Spaces & .Mac Sync Bug, for example, it’s translated to /spaces-.mac-sync-bug.html
Having multiple .’s in an article URL can be very problematic. So, I’d suggest not using it unless you want to constantly re-write post slugs.
Since I’ve already made the change here and on the PhoneNews.com Blog, they’re going to keep the .html at the end, I know how to edit the slugs. But, PhoneNews.com won’t use the .html extension for news… I can’t hold every writer’s hand to watch them make the edit in the slug. Not time productive and not useful… at least now you know what’s up in the world of canonical URLs and WordPress.