The following line exceeds a 68-char max and, thus, demands folding:
123456789012345678901234567890123456789012345678901234567890123456789

This line ends with a backslash \

This line ends with a backslash \
\ This line begins with a backslash

The following is an indented 3x3 block of backslashes:
   \\\
   \\\
   \\\