Punctuation in the English language helps the reader to understand a sentence through visual means other than just the letters of the alphabet.
These two styles differ mainly in the way in which they handle quotation marks with adjacent punctuation and the use or omission of the full point (period) with contraction abbreviations.
[5] Open style dominates in text messaging and other short-form online communication, where more formal or "closed" punctuation can be misinterpreted as aloofness or even hostility.
Brackets (⟨[ ]⟩, ⟨( )⟩, ⟨ { } ⟩, ⟨ ⟨ ⟩ ⟩) are used for parenthesis, explanation or comment: such as "John Smith (the elder, not his son)..." The colon ⟨:⟩ is used to start an enumeration, as in Her apartment needed a few things: a toaster, a new lamp, and a nice rug.
It is also used, as the full point, to indicate abbreviation, including of names as initials:[10] Dwight D. Eisenhower's home in Gettysburg, Pa., was not very far from Washington, D.C.The frequency and specifics of the latter use vary widely, over time and regionally.
For example, these marks are usually left out of acronyms and initialisms today, and in many British publications they are omitted from contractions such as Dr for Doctor, where the abbreviation begins and ends with the same letters as the full word.
In computing, the dot is used as a delimiter more broadly, as site and file names ("wikipedia.org", "192.168.0.1" "document.txt"), and serves special functions in various programming and scripting languages.
In British publications (and those throughout the Commonwealth of Nations more broadly), periods and commas are most often treated the same way, but usage varies widely.
"[13][unreliable source] It goes on to recommend "British" or logical quotation for fields such as linguistics, literary criticism, and technical writing, and also notes its use in philosophy texts.