Overground
https://tmrail.teresco.org/hb/index.php?sys=gbnloOff-peak service pattern with list names and route names
Romford to Upminster route =
Romford - Upminster Shuttle Liberty Line
Watford Junction to Euston route =
Watford DC Line Lioness Line
Richmond and Clapham Junction to Stratford route =
North London Line Mildmay Line
Gospel Oak to Barking Riverside =
GOBLin / Gospel Oak to Barking Line Suffragette Line
Highbury & Islington to New Cross, Clapham Junction, Crystal Palace and West Croydon route =
East London Line Windrush Line
There's also a twice daily (more on Saturdays, none on Sundays) service to Battersea Park, it would have unique track mileage (which I've clinched), but it just seems too irregular compared to the regular services in the surrounding area at 30+ times a day (if not 60+) to include - advice wanted.
Liverpool Street to Enfield Town, Cheshunt and Chingford route =
Lea Valley Line Weaver Line
New signs forthcoming when someone makes Wikimedia Commons versions of these signs.
I don't know how they will be shown in in-car line diagrams (ie the block colour, rather than the line above) as there's zero renders of those in public.
edit: 2024-02-15 lines officially renamed