Lab 1.1 Questions

Took LF101x through EDX and now just starting the LF201 1.1 lab while using CentOS8. I am a novice at Linux, but I had a few questions:

The lab instructions instruct me to navigate to /etc/sudoers.d and add my "student" file there. I added ruefio.txt and edited with the content "ruefio ALL=(ALL) ALL" per instructions. As I read other sources on how to do the same thing, I see quite a few differences. Some recommend "ruefio ALL=(ALL:ALL) ALL" or some variant of. Is this just a syntax preference or does these slight changes mean something?

Secondly, I tested to see if I gave my account proper permissions by using "sudo -l -U ruefio" and received the following:

User ruefio may run the following commands on centos8:
(ALL) ALL
(ALL) ALL

Why does it repeat itself? Is that right?