bufferbegin
begin
(default)

Begin redirecting display to an internal output buffer.  In another word, stop displaying and instead, build a display string internally.

The output buffer can be accessed via the sys%output:content variable.  Its length (number of characters in it) is in sys%output:length.

bufferend
end

Display the output buffer onto the web page, destroy the content of the output buffer and stop further display redirection to the output buffer.

buffercancel
cancel

Destroy the content of the output buffer without displaying it, and stop further display redirection to the output buffer.

now

Flush the output to the client.  (Server platform and client browser dependent.)

instantly

Flush after each output (as if using "output now" after every "display").  This will implicitly assume an "output bufferend" so that all buffered content will be output at once and buffering will end immediately.

Note: On some platform, using "output instantly" may have an impact on performance.

noninstantly

Turn off "output instantly", which means to display output according to the platform and browser default behaviour in bufferring.