@lyse@lyse.isobeef.org its a hierarchy key value format. I designed it for the network peering tools i use.. I can grant access to different parts of the tree to other users.. kinda like directory permissions. a basic example of the format is:

@namespace
# multi
# line
# comment
root :value

# example space comment
@namespace.name space-tag 

# attribute comments
attribute attr-tag  :value for attribute

# attribute with multiple 
# lines of values
foo :bar
      :bin
      :baz

repeated :value1
repeated :value2

each @ starts the definition of a namespace kinda like [name] in ini format. It can have comments that show up before. then each attribute is key :value and can have their own # comment lines.
Values can be multi line.. and also repeated..

the namespaces and values can also have little meta data tags added to them.

the service can define webhooks/mqtt topics to be notified when the configs are updated. That way it can deploy the changes out when they are updated.

I can query the configurations a few different ways. i can request the specific name foo.bar or a glob like foo.* or trace the hierarchy trace:some.deep.name.space which will give me the namespaces some, some.deep, some.deep.name, and some.deep.name.space. These can be combined.

and then i have a compact version that makes things more grep’able in scripts.