[intraweb-iwml] can be used with or without a closing tag. If used with a closing tag, please refer to the (content) parameter below.
[intraweb-iwml] can be used with a closing tag to surround inline IWML content.
Note about pre. WordPress (at least TinyMCE Advanced) does not encode the <> in pre but they need to be.
URL that specifies the IWML to load and render.
Source and (content) are mutually exclusive. If both are specified, (content) will be ignored and source will be used.