Serial commas
The serial, or Oxford, comma is used to set off the final item in a list of three or more items. It is placed after the penultimate item and before the coordinating conjunction (usually and or or). Examples:
The event is free for students, alumni, faculty, and staff.
Notwithstanding the reference to Oxford, the serial comma is more frequently used in American than British English, where it is generally included only when necessary to prevent confusion. For instance, in the famous example I would like to thank my parents, Ayn Rand and God, the lack of a serial comma could potentially lead readers to think that the phrase my parents was being used in apposition to Ayn Rand and God.
Another example might be in a list in which each item consists of multiple words, such as Protection of human rights, impact of AI, and corporate social responsibility in the cross-border sphere. Although not strictly necessary, the serial comma here adds clarity by making it immediately apparent that the word impact refers only to AI and that corporate social responsibility is a separate item in the list. In doing so, it ensures a smoother reading experience by eliminating any ambiguity that might cause a reader to step back from the text to parse the exact meaning.
In general, it is UOC policy to follow British English usage in this regard and to use the Oxford comma only when required for clarity, as in the examples provided.