Should bundle identifiers be lowercase or camelcase?

Question

Say I have an app named "Foo Bar", should the bundle identifier be com.tyilo.foobar or com.tyilo.FooBar?

What is the most normal and what does Apple do?

Answer 1

You can do any but to make life simpler and prevent common mistakes it's just easier to keep it all lower case..

But it's entirely up to you what case you use?. The only gain from using lower case is what I mentioned above

Answer 2

I would make it the lower case not only to make your life simpler but also because bundles are reverse domain name and URLs are case insensitive up to and including the TLD (com/org/net) and most browsers display URLs as all lowercase.

Also if you look at Apple's sample code they use all lower case.

com.example.apple-samplecode