This sets the charset used to display search results in. The
default if empty is the charset for Storage Charset under All Walk
Settings. This charset should be a superset of US-ASCII (same
7-bit sequences), compatible with Top HTML, and translatable by
the Search Appliance from Storage Charset.
A <META HTTP-EQUIV=Content-Type> tag in Top HTML will be
updated automatically to reflect this charset. This update can be
disabled by putting 2 or more spaces between META and
HTTP-EQUIV in Top HTML.
Note that if the Display Charset differs from the Storage Charset,
search results must be converted on-the-fly, potentially degrading
performance slightly. Thus, if Display Charset is ever changed, it is
recommended that Storage Charset be changed as well, and after the
next rewalk (when all the database data is now in the new Storage
Charset), Display Charset be change back to default (empty, which will
still display in the new Storage Charset).