Comment by klauserc

Isn't that example the exact opposite of mixing content and presentation? The * notation applies the strong [emphasis] tag, the show rule (re-)defines the presentation. Ideally you would of course separate the two into separate files (template + content).

In my time using Typst, I found that Typst makes it possible/easy to make content even more abstract: write the content as a "data structure" and then present parts of it in various places around your document. For instance to list quantity/weight of a parts description in a parts index at the end.