Probably the homeserver.yaml file, as yaml is a standard format where indentation matters, and is always 4 spaces.

    # cat /etc/matrix-synapse/homeserver.yaml|wc -l
    1611
    # cat /etc/matrix-synapse/homeserver.yaml| grep -v '^\s*#\|^$' | wc -l
    101

The config file is just well-commented.