Comma (,):
Means "and". Use this if you want all the conditions of your macro to be true.
Semi-colon (;):
Means "else". Use this if you know some of the conditions in your macro aren't going to be true.
Bracets ([]):
These enclose your conditions. These usually come before your parameters. Sometimes these can be empty to make sure there is always a true condition.
At Symbol (@):
Means "at". Use this to set your target. This also means "target="
Exclaimation Mark (!):
Toggles abilities such as autoattacking, shooting, stealth, etc.