[ludocode]

That's only in C++. As far as I know in C you need to name all parameters (although maybe that rule has been relaxed in newer versions of C.)

[flohofwoe]

C23 finally relaxes that rule:

https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2510.pdf

(although some C compilers already allowed it in non-pedantic mode)