Apple has updated their T2 knowledge base article:
https://support.apple.com/en-us/HT208862
Tag: T2
How to determine if a Mac has the Apple T2 security chip
Here’s an article that describes how you can check if an Apple system is T2-based or not:
https://www.idownloadblog.com/2018/11/20/mac-models-t2-chip-howto/
Duo Security on Apple T2 chip
Apple publishes whitepaper on T2 security chip
Apple: new/updated T2 chip and Secure Boot support articles
Re: https://firmwaresecurity.com/2018/07/12/apple-releases-new-systems-with-t2-chip-and-uefi-secureboot/ and
https://firmwaresecurity.com/2017/12/20/apple-kb-article-on-secure-boot/
the latter Apple support article on Secure Boot has been updated recently:
About Secure Boot
https://support.apple.com/en-us/HT208330
Firmware Security 