If you want to see html only content use this htaccess rules:
RewriteEngine on
RewriteCond %{REMOTE_ADDR} x.x.x.x
RewriteRule ^$ doku.php [L]
RewriteRule ^$ doku.php?do=export_html [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REMOTE_ADDR} !x.x.x.x
RewriteRule (.*) doku.php?do=export_html&id=$1 [QSA,L]
RewriteRule ^index.php$ doku.php?do=export_html
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REMOTE_ADDR} x.x.x.x
RewriteRule (.*) doku.php?id=$1 [QSA,L]
RewriteRule ^index.php$ doku.php
For everybody will be html view, and for ip address x.x.x.x default view