Tomy/Trackmaster Serial Number types and meanings

When we usually get our engines, they usually have a serial number on them somewhere, does anyone know the meaning of one?

Here's the examples:

TOMY (19??-2014)



Plarail (2015-Present)
Does anyone know of a serial number has any meaning to our Tomy/Trackmaster models?

Hi Trainboy .. This is not serial number but it shown manufacturing date from factory. 

A10 
Production in Jan.' 10
-A (month): January
-10 (Year) : 10 (1910 or 2010 ?)
 
* Paper printed in body cover: no more since year 2017




E 25 19
Production in 25 May 19
E : May  / L= Dec.
19 : Year 19 (2019)
* Punching on chassis and all motor area : started in year 2016



271E8
Production in the 271th day in year 8 from factory E 
271 : the 271th day (1 Jan =1, 31 Dec.=365)
E : Factory code
8 : Year 8