Links between pages of your structure use a page identifier to name the page they are pointing at. Page identifiers may have one of two forms:
For a page in the starting directory, the page
identifier is the name of the file without its
.g suffix.
For a page in some other directory, the page identifier has the form
topic/basename
where the is the name of the file without its
basename.g suffix, and the is the
topic name for the directory where that file lives.
topic
Keep in mind that for first-level directories under
the starting directory, the default topic name is the
same as the directory name. For example, if your
starting directory is /u/bart/public_html/, the topic name for
input file /u/bart/public_html/bottles/klein.g
would be bottles/klein.