PATTERN FILL                                                       <Alt>+L

  This function allows you to fill an area using various patterns. Before
  you can perform this operation, you have to have selected a pattern to use
  by pressing <Shift>+<Alt>+L - this will display all the pattern files
  available. Once you have selected a pattern, <Alt>+L will always fill
  using that pattern until you select another pattern.

  Note that many of the patterns are dependant on the current colour
  settings - usually these settings will effect the colour of the pattern
  displayed, but sometimes the colour may be used to express density (e.g.
  the star pattern), or other attributes. The colour of the character below
  the cursor, or the actual character below the cursor may also effect the
  pattern.

  All this info (for the patterns provided with SDES) should be documented
  in one of the appendices, although any third party patterns you obtain
  will probably have their own docs.