A Land Far Away

I found this exceptional work on Ilmater. I think it is a wealth of information and would like to ask which part of its content is canon and which is custom content.

Thanks in advance for your time.

Ilmater's Church information

No, it's not all canon, but there are canon bits in there. It's been more fleshed out for a specific campaign (Northern Journey). The best source for Ilmatari lore is Faiths and Avatars (AD&D 2nd edition) Forgotten Realms book.