What is the abbreviation for possessive nouns?

The abbreviation for possessive nouns is typically formed by adding an apostrophe followed by the letter "s" (e.g., "John's" for John’s book). If the noun is plural and already ends in "s," only an apostrophe is added (e.g., "dogs'" for the dogs' toys). There isn't a specific standard abbreviation beyond this usage, as possessive forms are generally expressed in full.