17 · Instance configuration

The engine and the site are two different things. The site supplies its name, address, language, navigation, colours, contact address and chosen policies; the engine knows none of those values and has none of them written anywhere on its side.

That separation is sharper than it looks at first glance. A value written into the engine's code reaches the browser even when nobody displays it — because whether it displays is decided only at run time, and the build tool cannot cut away a branch it has no way of predicting. A site run under a pen name cannot afford such a souvenir in its output.

The practical consequence: a new instance is a new configuration file and a new content directory, not a fork of the engine with the names cut out. A fix in the engine reaches every deployment by the same road.