Include the leading forward slash „/”, even if your file is located in the root of your theme.
Be sure that you define the type correctly, as your site will not validate without it.
<a href="<?php the_permalink() ?>" rel="bookmark">
<?php the_title(); ?></a>
If you do this, you will almost surely need to maintain several versions of this reference because different parts of the displayed content are generated from different locations. For example, pages are created from .php template files in the WordPress root directory (note that this is not the webserver’s document root), while posts are created from .php template files in the chosen theme’s directory („/path-to-wordpress-root/wp-content/themes/yourtheme/partofpost.php”). These are two different paths.
If you choose No Formatting, your post’s text will run together, so you will have to add paragraph tags and other HTML tags in order to format your page, as WordPress normally does that for you.
If you are having trouble with this, the WordPress Support Forum may be able to help.