Shinking a partition

[Olivier]

Hello,

Is it possible to shink a partition under FreeBSD?

I found only one reference that seems to say it is possible 
https://unix.stackexchange.com/questions/324308/resizing-root-partition

but whenever I try, growfs complains that the new size is smaller than
the original size/

So, I am wondering if it is another case of "don't trust what you read
on the web"?

Thanks in advance,

Olivier