# Help Desk

Help Desk is a complete source of information about PLT software, including DrScheme, MzScheme, and MrEd.

Use Help Desk to find information in either of two ways:

1) Navigate the Help Desk information pages by clicking on hyperlinks.

- Use the `Rewind` and `Forward` buttons to retrace your steps.
- The `Home` button always takes you back to the starting page.

2) Search for terms using the `Find docs for` field at the bottom of Help Desk.

- Enter one or more terms into the `Find docs for` field.
- Click the `Search` button (or type Enter or Return) to start a search.
- Help Desk scans the information pages and returns a list of hyperlinks for keyword, index entry, and raw text matches:
  - Keywords are Scheme names, such as `define` and `cons`.
  - Index entries are topical phrases, such as "lists".
  - Raw text results are fragments of text from the information pages. (Raw text results are useful only as a last resort.)
- Expert users can adjust the search with the popup-menu controls to the right of the `Search` button.

Help Desk sorts search results according to their source, and then according to their (apparent) relevance.