-`ikiwiki` is a wiki compiler. It builds static html pages for a wiki, from `source` in the [[MarkDown]] `language`, using the specified html `templates` and writes it out to `destination`.
+`ikiwiki` is a wiki compiler. It builds static html pages for a wiki, from
+`source` in the [[MarkDown]] language, and writes it out to `destination`.
+
+Note that most options can be shortened to single letters, and boolean
+flags such as --verbose can be negated with --no-verbose.
+
+# MODE OPTIONS
+
+These options control the mode that ikiwiki is operating in.
+
+* --refresh
+
+ Refresh the wiki, updating any changed pages. This is the default
+ behavior so you don't normally need to specify it.
+
+* --rebuild
+
+ Force a rebuild of all pages.
+
+* --cgi
+
+ Enable [[CGI]] mode. In cgi mode ikiwiki runs as a cgi script, and
+ supports editing pages, signing in, registration, and displaying
+ [[RecentChanges]].
+
+ To use ikiwiki as a [[CGI]] program you need to use --wrapper or --setup
+ to generate a wrapper. The wrapper will generally need to run suid 6755 to
+ the user who owns the `source` and `destination` directories.
+
+* --wrapper [file]