Period Punctuation
The sentence-ending rule is simple; the exceptions are mostly formatting and house style. Use a period to close ordinary declarative sentences, then check the relevant style guide for abbreviations, lists, headings, captions, interface text, web addresses, and other special contexts.
Use a period—called a full stop in many varieties of English—to end a complete statement that is not a question or exclamation. Periods also appear in some abbreviations, references, numbers, and list contexts, but headings, captions, simple list items, URLs, and digital endings can follow style-specific rules.
Key details
Further guidance
Headings And Labels
Many digital and editorial systems omit periods from headings, interface titles, captions, and other stand-alone labels.
Lists
Whether list items take periods depends on whether they are sentences, fragments that complete a lead-in, or stand-alone labels; follow the governing style consistently.
Sentence End
End a complete statement with a period when it is not functioning as a direct question or exclamation: “The meeting begins at nine.”
Urls And Abbreviations
Do not assume every abbreviation needs periods, and take care not to make sentence punctuation look like part of a bare URL or email address when the style guide tells you to avoid that ambiguity.
Worked Example
Sentence: “Submit the form by Friday.” Heading: “Submission deadline” rather than “Submission deadline.” The mark changes because the second line functions as a heading, not a sentence.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Full stops (opens in a new tab)Australian Government Style Manual · Current government guidance covers the full stop/period as sentence-ending punctuation plus selected decimal, reference and list contexts, while excluding it from some headings, captions, hashtags and other digital endings.
- Periods (opens in a new tab)Microsoft · Current technical-style guidance ends sentences with periods but omits them from headlines, headings, UI titles and simple lists, confirming that some uses are style- and content-type-dependent.