This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
What to store in the extension?¶
For TypoScript we have to distinguish between configuration that is specific for a particular server (assuming that we have at least a development installation and a live website) and what is common for the website. It could very well be that we need to set the absRefPrefix and that it's different for the development installation compared to the live site. Then we'll store that in a constant in a TypoScript template record. In the .ts files we'll use this constant as usual. In the end we can simply install the same sitepackage extension on both installations and still have the correct setting.