When should you use a period after an abbreviation?

When should you use a period after an abbreviation?

A period should be used after an abbreviation when it is used as an abbreviation for a specific word or phrase. This includes abbreviations for titles (e.g., Mr., Mrs., Dr.), measurements (e.g., ft., in., lb.), and commonly used abbreviations (e.g., etc., e.g., i.e.). However, it is important to note that some abbreviations, such as acronyms (e.g., NASA, NATO), do not require a period. Additionally, if an abbreviation is used at the end of a sentence, the period after the abbreviation serves as both the abbreviation's period and the sentence's ending punctuation.