The name of the 340 was due to the number of methods that existed. It has since been altered and expanded, but the name stayed the same.
No it was not.
Hopefully you are kidding.
We use to laugh our azzes off at Union BAs talking about "What if the driver did 339 of the 340 methods right?"
Each operation Standard Practice Manual (SPM) published by the I.E. department has a number assigned to it.
Package Pickup and Delivery Operations Manual is assigned the number 340.
Central Sort (Hub) SPM is assigned the number 260.
There is one for Carwash.
There is one Trailer Delivery and Pickup.
There are not 340 SPMs.
The lowest I remember seeing was SPM 40.