As far as I know a Schuko socket can have live on either the left or right (looking at it), but there's a strong convention for having it on the right.
Partly this is compatibility between
CEE 7/3 and 7/5 and 7/7[1], The Netherlands almost universally using the first.
I have a socket tester designed for Schuko (similar to, but not exactly [2]), it (and AFAICT this is universal among them) enforces "live on the right".
What is definitely standardized us that the wires in your wall should be brown=live and blue=neutral (in the UK and European continent, other places may differ).
Once you start mixing up neutral and live in sockets it'll often lead to a mixup in the wall wiring, as sockets are often used as a starting point to extend wiring. I partially rewired my house to fix that issue, left by an electrician.
As an extra data point, e.g. Jung sells pre-wired sockets which assume that you follow this convention[3]. If you don't you'll end up with reversed wires in your wall, i. e. wires mixed up by color, not just the socket itself violating some convention of live=right.
The photo in [3] is low resolution, so you can't see the tiny "Jung" logo on the inner part of the socket, which indicates which side is up.
Partly this is compatibility between CEE 7/3 and 7/5 and 7/7[1], The Netherlands almost universally using the first.
I have a socket tester designed for Schuko (similar to, but not exactly [2]), it (and AFAICT this is universal among them) enforces "live on the right".
What is definitely standardized us that the wires in your wall should be brown=live and blue=neutral (in the UK and European continent, other places may differ).
Once you start mixing up neutral and live in sockets it'll often lead to a mixup in the wall wiring, as sockets are often used as a starting point to extend wiring. I partially rewired my house to fix that issue, left by an electrician.
As an extra data point, e.g. Jung sells pre-wired sockets which assume that you follow this convention[3]. If you don't you'll end up with reversed wires in your wall, i. e. wires mixed up by color, not just the socket itself violating some convention of live=right.
The photo in [3] is low resolution, so you can't see the tiny "Jung" logo on the inner part of the socket, which indicates which side is up.
1. https://commons.m.wikimedia.org/wiki/File:European_plug_and_...
2. https://amzn.eu/d/1HuzNPJ
3. https://www.elektramat.nl/jung-dubbel-stopcontact-met-randaa...