. The primary component implies the name in the command and the 2nd element in braces sets an option for this command. The choices differ from command to command and you'll master some of them afterwards Within this tutorial. finish doc finish environment1 % Also invalid: start out natural environment https://tabletennistableshop.co.uk/2023/09/21/latex-catsuits-a-modern-twist-on-classic-elegance/