-VT100-series terminals allow the server to send control sequences
-that shift temporarily into a separate character set for drawing
-lines and boxes. PuTTY has a variety of ways to support this
-capability. In general you should probably try lots of options until
-you find one that your particular font supports.
+VT100-series terminals allow the server to send control sequences that
+shift temporarily into a separate character set for drawing simple
+lines and boxes. However, there are a variety of ways in which PuTTY
+can attempt to find appropriate characters, and the right one to use
+depends on the locally configured font. In general you should probably
+try lots of options until you find one that your particular font
+supports.
+
+\b \q{Use Unicode line drawing code points} tries to use the box
+characters that are present in Unicode. For good Unicode-supporting
+fonts this is probably the most reliable and functional option.
+
+\b \q{Poor man's line drawing} assumes that the font \e{cannot}
+generate the line and box characters at all, so it will use the
+\c{+}, \c{-} and \c{|} characters to draw approximations to boxes.
+You should use this option if none of the other options works.