AER style is to use the serial comma (also called the Oxford comma). This is the comma that precedes the final item in a list of three or more items.
Wrong: oil, gas and coal exploration
Right: oil, gas , and coal exploration
Put a comma after locations if the city and province (for example) are provided, and after the day and year if the month, day, and year are provided. If only the month and year are given, no comma is necessary. (See the Dates and Times section for additional information.)
It’s 25 kilometres north of Cold Lake , Alberta , in the M.D. of Bonnyville.
We will hold a public hearing on May 23 , 2019 , at 9:00 a.m.
But: ST98 was released in May 2019 to great fanfare.
The abbreviations i.e. (that is) and e.g. (for example) should always be followed by a comma.