The new rules regarding parcels sent from Switzerland are in force since 01.01.2020. Now, to send even a small parcel abroad ( a book to a fellow Bookcrosser, for example :) ), one has to register its contents online first, or pay extra CHF 3 at the post office counter.
Swisspost has created an informative video to show how it works now: https://www.post.ch/---/declaration-and-clearing-through-customs?...

This initiative is brought up by the Universal Postal Union ( regulates worldwide postal traffic), so please check in your country, whether the same rules now apply.

Filling in the online customs declaration, I have discovered that packages can only contain 3 items. You also need to know the phone number of the person you are mailing the package to (the form won't go through without it), wich puts an end to any surprises, unless you already know the number.
Such a nuisance: I had to reopen my package and remove the caramels and tea.

So annoying, right? I group items together ( tea+caramels, for example), and put in my phone number.

put in my phone number

what a good idea!