Once you press F12, you enter the incremental search mode. Once in the incremental search mode:
• F12 will search again for the current string, or it will load the current string with the previous one if the current string is empty.
• Shift+F12 will search backwards.
• Backspace reduces the search string.
• Esc will cancel and return to the initial position.
• Enter will stop and leave the selection at its current position.
• Any key that maps to a command will exit the incremental search mode and leave the selection at its current position, and then the command will execute.
• Any other simple key is added to the current search pattern, which is displayed at the bottom in the status bar.
• The search buffer is left with the last successful search pattern.
The incremental search pattern is not case sensitive, unless you type an uppercase character.