engraving on jug? what's does it mean?

[yamarider]

On the base of the jug there is a number engraved in it. it's either 262 or z62 i'm not sure. I'm assuming that this is an indication that the top end was rebuilt before, but what does this number mean? thanks

 

[xj4m3]

i noticed that its on mine too but i have no clue what it means