4 Searches your code to see if you are using techniques that are no longer approved by Rails.
6 Gently warns you and advises you about what you should do instead.
12 A report will be printed to the screen.
16 http://nubyonrails.com/pages/deprecated
21 * Use pure Ruby so it works on Windows
22 * Make criteria more specific
23 * Update to check for new items that are deprecated in edge
24 * A test assertion that does the check