Serial comma toast. Adding a serial comma removes this ambiguity. Writers who normally avoid the serial comma often use one in these circumstances, although sometimes re-ordering the elements of such a list can help as well. In some circumstances using the serial comma can create ambiguity. If the book dedication above is changed to the serial comma after "Ayn Rand" creates ambiguity about the writer's mother because it uses punctuation identical to that used for an appositive phrase, leaving it unclear whether this is a list of three entities (1, my mother; 2, Ayn Rand; and 3, God) or of only two
Punctuation of English in text messaging and other short-form online communication, where more formal or "closed" punctuation can be misinterpreted as aloofness or even hostility. Open punctuation eliminates the need for a period at the end of a stand-alone statement, in an abbreviation or acronym (including personal initials and post-nominal letters, and time-of-day abbreviations), as well as in components of postal addresses. This style also eschews optional commas in sentences, including the serial comma. Open punctuation also frequently drops apostrophes. Open punctuation is used primarily in certain forms of business writing, such as letterhead and envelope addressing, some business letters, and résumés and