The "/whatis" page:

Typical usage:

   /artifact/HASH
   /whatis/HASH
   /file/NAME

Additional query parameters:

  ln              - show line numbers
  ln=N            - highlight line number N
  ln=M-N          - highlight lines M through N inclusive
  ln=M-N+Y-Z      - highlight lines M through N and Y through Z (inclusive)
  verbose         - show more detail in the description
  download        - redirect to the download (artifact page only)
  name=SHA1HASH   - Provide the SHA1HASH as a query parameter
  filename=NAME   - Show information for content file NAME
  fn=NAME         - "fn" is shorthand for "filename"
  ci=VERSION      - The specific check-in to use for "filename=".

The /artifact page show the complete content of a file
identified by HASH as preformatted text.  The
/whatis page shows only a description of the file.  The /file
page shows the most recent version of the file or directory
called NAME, or a list of the top-level directory if NAME is
omitted.