Hi there,
The special characters on your website URL is changed because URLs are sent over the Internet using the ASCII character-set. That's why the & is converted to %26.
If you're trying to make your site rank, it is better to just simplify or shorten the URL. This is because search engines have problems indexing sites when the URLs contain special characters.
The special characters below are known to be "search-engine-spider-stoppers":
- ampersand (&)
- dollar sign ($)
- equals sign (=)
- percent sign (%)
- question mark (?)
Hope that helps!