Don't put Capitals in File Names

It Destroys Keyword Ranking

Domain names are not case sensitive so all hosting servers will change the capitals in domain names to lower case. However this is not the case with file names.

Some people write their file names like this:
www.ExampleSite.com/FileNameGoesHere.html

Microsoft IIS servers can handle capitals in file names because they automatically change them to lower case, but not sites hosted on Apache servers.

When file names are spelled out with capitals for websites hosted on Apache servers they produce 404 errors. Duplicate content penalties will result because search engines, and particularly Google, will think there are two different pages with the same content. This reults in reduced keyword ranking for all affected pages.

If your site is hosted on an Apache server and you have ever sent a URL similar to the one above to someone and they couldn't open the page, this is likely the reason.

You can 301 redirect those affected URLs or rewrite them via htaccess so they automatically change capitals to lower case but any redirect will cause a delay of weeks or months for the search engines to sort out and thus further delay keyword ranking.

So it's better to never use capitals in file names, even if you are on a Microsoft IIS server, because if you ever move your site to an Apache server you'll have to rewrite all the URLs.