KernelNewbiesTW:

Headlines

Input

= First headline level with =-character =
== Second ==
=== Third ===
... (up to "Fifth")

Display

First headline level with =-character

Second

Third

... (up to "Fifth")

If a headline isn't displayed correctly, it is usually because:

there are invisible (whitespace) spaces after the concluding =-character (they can be deleted manually or with "Remove trailing whitespace from each line" edit option).
the number of =-characters at the front and at the back doesn't match.