A few questions on Documentation

#1

Hi, I have been setting up Hydra and going through all the API docs and Setup of Hydra. I have a few questions that I cannot seem to find the answers to. If you could point me to the place where I can have these questions answered that would be great Thanks.

  1. What is the Environment variable SECRETS_SYSTEM used for?
  2. Are there any custom fields that I can add to a Client definition?
  3. if there aren’t any custom fields which fields stored by client can I use that won’t affect Hydra’s work flow? ie can I use owner or contacts how ever I wish?
  4. More the API docs is there a definition listing of each field ie values and how they affect workflow?

Any help with these questions would be great. thanks