Call me a bit obsessive but I use the set numbers as a categorization scheme... here's how to make some sense out of them.
|1000||Freight and passenger cars. Basic rolling stock. To be in the 1000 range an item should be unpowered, and should be primarily intended for rail operation. This refers to the main item, not the load (if any).|
|2000||Locomotives. Should be powered (at least simulated) and not be a combination unit that also carries freight or passengers, if so it goes in 3000.|
|3000||Self Propelled rail vehicles. Street cars, gas electric railcars and the like|
|4000||Structures. May be rail themed or not|
|5000||Non rail vehicles. Note that a hirailer, should I ever do one, would probably go here, rather than in 3000 (although you could make that case)|
If you find this confusing please let me know. Email me with your wishes, desires and suggestions.