Do Periods Go Inside Quotes?

In the United States, periods and commas go inside quotation marks--unless you are asking reader to input data. Then, the period or comma goes inside the quotation mark ONLY if you want it input with the rest of the information. Examples:

Most fairy tales start with the words, "Once upon a time."

Input "xyz330". Means the period is not to be input.

Input "xyz330." Means to input the period.