I was testing a website I'm developing in Firefox ( latest version + nightly), and I have weird squares around text : 

![enter image description here](https://i.stack.imgur.com/ccN2i.png)

When I try to copy - paste it, it seems to be an empty space

I use this doctype, like other website I develop...

```
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
[....]

```

Here a fiddle : <http://jsfiddle.net/SCr7F/>