Recently I wrote a reference post for Tamar’s Introduction to Google’s Webmaster Central. I just copied its title and modified. What I hadn’t noticed is the smart quote (curly quote). Although WordPress Permalinks mechanism removes normal quotes (straight quotes), it does assign a weird code for smart quotes. So, my Permalink was like below,

/an-introduction-to-google%e2%80%99s-webmaster-central/

So, I had to change the post slug to remove unnecessary characters. Now it appears like below. (This would be the same Permalink I get if I had included a normal quote rather than a smart quote)

/an-introduction-to-googles-webmaster-central/

I didn’t create a 301 redirection since the post was new. But if you make this change to a old post which has been referenced everywhere (in other web sites) then you will really need to create one since you may loose visitors and search engine crawling.