Assembly drawing number conventions

[Shady99]

Hello,can someone tell me what's the convention for numbering an assembly drawing...like the drawing no consists of hierarchy of sub assemblies and assemblies in the main assembly. For example
Xyz-00-12-23-34

 

[CWatters]

Each company I've worked for had their own numbering system.

Google suggests you check out..
https://www.nationalcadstandard.org/ncs6/