dbt – what is +/- in YAML files?

In DBT YAML file such as dbt_project.yml, what is + or - sign of the element?

models:
  # Be sure to namespace your model configs to your project name
  dbt_labs:

    # This configures models found in models/events/
    events:
      +enabled: true            # <--- What is the meaning of +?
      +materialized: view       # <--- What is the meaning of +?

      # This configures models found in models/events/base
      # These models will be ephemeral, as the config above is overridden
      base:
        +materialized: ephemeral       # <--- What is the meaning of +?

>Solution :

"-" is standard YAML syntax, indicating a "list" item: docs.ansible.com > YAML Basisc

"+" is DBT-specific, indicating a sub-category like "+indexes", "+tags". It’s just a DBT convention. docs.getdbt.com > Materialize Configs.