I recently started using arguments in my main program (here written in C++ but could be any programming language)

#include <iostream>

int main(int argn, char* argv[]) {
    // do stuff depending on argv[1], argv[2], etc.
}

For now I am using mostly random naming conventions like -t for testing, -d for debugging, -l for printing logs e.g. There is no need for adding -, it is just that most shell parameters are named that way. I also use -- for second parameters.

Is there any established naming conventions for main arguments ?