I'm developing a CMS that required i18n support. The translation strings are stored as an array in a language file (ie, en.php). Are there any naming conventions for this..

How can I improve on the sample language file below...

 // General
 'general.title' => 'CMS - USA / English',
 'general.save' => 'Save',
 'general.choose_category' => 'Choose category',
 'general.add' => 'Add',
 'general.continue' => 'Continue',
 'general.finish' => 'Finish',

 // Navigation
 'nav.categories' => 'Categories',
 'nav.products' => 'Products',
 'nav.collections' => 'Collections',
 'nav.styles' => 'Styles',
 'nav.experts' => 'Experts',
 'nav.shareyourstory' => 'Share Your Story',

 // Products
 'cms.products' => 'Products',
 'cms.add_product' => 'Add Product',

 // Categories
 'cms.categories' => 'Categories',
 'cms.add_category' => 'Add Category',

 // Collections
 'cms.collections'=> 'Collections',
 'cms.add_collections' => 'Add Collection',

 // Stylists
 'cms.styles' => 'Stylists',
 'cms.add_style' => 'Add Style',
 'cms.add_a_style' => 'Add a style',

 // Share your story
 'cms.share_your_story' => 'Share Your Story',

 // Styles
 'cms.add_style' => 'Add Style',