Functions like English 'John Doe' or 'Joe Bloggs' — a generic stand-in name for an unnamed person in hypotheticals, examples, jokes, and stories. The prefix
老 (literally 'old') is a friendly title for an adult, paired with the most common surname in China,
王, to evoke an ordinary middle-aged guy. Pair
老李,
老张, or
老刘 with
老王 when you need two or three placeholder characters in an example.