The Minor Planet Center designation for Comet Swift–Tuttle’s 1992 apparition is P/1992 S2.
Comet designations encode useful discovery and classification information. The initial P identifies a periodic comet, the year records the relevant designation year, the letter indicates the half-month of designation, and the final number gives the order within that half-month.
Swift–Tuttle also has earlier designations, including P/1737 N1 and P/1862 O1, reflecting its recorded appearances and the naming systems used for different returns. Its formal numbered designation is 109P/Swift–Tuttle.
The 1992 apparition was especially important because the comet was rediscovered and its orbit was connected with earlier observations. Once the comet’s identity and orbit were clarified, astronomers could more confidently identify it as the parent body of the Perseid meteor stream.