I will start making a list for linux then.
rm - ok for all ages.
grep - 18+, you can obviously use this to search for porn.
find - 18+, see grep.
reboot - ok for all ages.
echo - ok for all ages.
cat - 18+, prints the porn you found directly to your terminal.
sudo - 18+, obviously.
kill - ok for all ages. This is the US, right.
ps - 18+, no peeping at other processes.
rm - between -i and -r this is just a less efficient way to search for porn
reboot - you never know what the sysadmin might have loading on boot, unsafe as it could load porn
echo - ASCII art would like to have a word
kill - I know the US will have mixed feelings, but communicating with other processes might allow them to send you porn
ed - 45+ nostalgics only
rm needs to be 18+, kids could use it to cover their tracks.
>reboot - ok for all ages.
I'm not so sure, who knows what woke UEFI and edgy motherboard vendors are putting up as splash screens these days. And the law doesn't even consider those since they aren't part of the OS!
> echo - ok for all ages.
> cat - 18+, prints the porn you found directly to your terminal.
Sound good in theory, until you realise that any teenager knows perfectly well how to trivially get around the lack of `cat` to read their terminal smut: