Conventions of an Opening Title Sequence

I believe the conventions of an OTS are as follows:

• List the Distribution company or companies
• List the Production company 
• Credit Director
• Credit Top billing Actors or actresses
• Credit Producers or other major crew members
• Show the title of the film
• Set some form of atmosphere for the film
• Introduce the audience to the story and some characters (even if the scene is as simple as the protagonist walking through rain.