/static/scripts/tiny_mce/themes/simple/langs/en.js

 1tinyMCE.addI18n('en.simple',{
 2bold_desc:"Bold (Ctrl+B)",
 3italic_desc:"Italic (Ctrl+I)",
 4underline_desc:"Underline (Ctrl+U)",
 5striketrough_desc:"Strikethrough",
 6bullist_desc:"Unordered list",
 7numlist_desc:"Ordered list",
 8undo_desc:"Undo (Ctrl+Z)",
 9redo_desc:"Redo (Ctrl+Y)",
10cleanup_desc:"Cleanup messy code"
11});