So what does a suburban service serve if it is not the suburbs!
You seem to be assuming that there is no differences between a Inner Suburban service and a Outer Surburban service which there are and I will point out the differences using various examples so you can understand as it seems you with others can't tell the difference between a IC service and the two types of Suburban services!
A Inner Suburban service has a Metro layout and has a frequent stopping pattern often with stops quite close together as a example Waterloo to Weybridge or Moorgate to Stevenage via Hertford North, trains also don't have toilets.
A example of these trains are Class 313s, Class 455s etc...
A Outer Suburban service has a less intensive layout then the Metro layout and stops at less stops then the Inner Suburban service but more stops then the InterCity service often with a number of miles between stops as a example, Waterloo to Basingstoke or Kings Cross to Peterborough, trains DO have toilets.
A example of these trains are Class 365s, Class 450s etc...
Now a InterCity service has a IC layout and calls at far less stops then the Outer Suburban service often with 70 or so miles between stops for example London Euston to Manchester Piccadilly or London Paddington to Cardiff Central with more onboard facilities then the other two above such as a buffet/trolley service, onboard entertainment ie Beam and more comfortable seating.
A example of these trains are Class 390s, HSTs and Class 800s etc...
Also BR's view of the differences affecting the ECML are very much clear cut when they electrified the local services the official view was that the Class 313s operating Moorgate then all stations to either Welwyn Garden City or Hertford North was the inner suburban service with a ten minute frequency on the Moorgate to Wood Green section.
The Class 312s operating Kings Cross to Royston calling Finsbury Park, Potters Bar then all stations on a half hourly basis was the outer suburban service and this view was extended when Network South East operated their services to Huntingdon before extending them to Peterborough.
Also Inner Suburban services on the Midland Mainline serve London to St Albans/Luton with the Outer Suburban services serving London then St Albans/Luton then all stops to Bedford so now the lesson is finished maybe we can continue discussing the Thameslink timetable rather then going off topic?