Case-insensitive searching in vi

By default, all searches in vi are case-sensitive. To do a case-insensitive search, go into command mode (press Escape), and type :set ignorecase. You can also type :set ic as an abbreviation.

To change back to case-sensitive mode, type :set noignorecase or :set noic in command mode.

If you tend to use this feature a lot, consider putting set ignorecase into your vi configuration file. See the article on customizing vi.