Taking a look at the TEC section of the A/FD, we can see that Santa Monica November Routes 22 through 27 all serve the same destination airports from KSMO. So which one does a pilot pick or expect? That will depend on two factors: What broad class of aircraft the pilot is flying and what the wind patterns in the area are.
The far right column lists the aircraft class that will be assigned that particular route, as well as the altitude assignment to expect. The code is given at the beginning of the TEC section, with J-jet, M=tubroprop, P=non-jet with a cruise speed 190 knots or greater, and Q=non-jet with a cruise speed 189 knots or less.
Reading the chart, any non-turbine aircraft (PQ) flying to KSAN can expect the SMON 22, 23, or 27 only, all to be flown at 5000 feet. Which one depends on the traffic flow at Los Angeles and Santa Monica. Normally LAX lands and departs to the west. When in an east operation, different routes are required for traffic flow, thus the notation (LAXE) in the SMON23 route. Likewise, if Santa Monica is landing north, the SMON27 is to be used.
Just to keep things really confusing, different geographical areas split TEC routes up by totally different aircraft classes. So in the Northeast, 210 and 250 knots delineate different route assignments, and singles may get a different route than a twin.