* In practice, this largely means that references are fully qualified in the API. IP Addresses (generally) have a network associated with them, node names have a cluster associated with them, etc.

## Reading a `.env` file

If you have many settings that possibly change a lot, maybe in different environments, it might be useful to put them on a file and then read them from it as if they were environment variables.

This practice is common enough that it has a name, these environment variables are commonly placed in a file `.env`, and the file is called a "dotenv".

!!! tip

    # ID post-install.
    #
    # If the mesh admin does not specify a value, Istio will use the value of the
    # mesh's Trust Domain. The best practice is to select a proper Trust Domain
    # value.
    meshID: ""

    # Configure the mesh networks to be used by the Split Horizon EDS.
    #

    # ID post-install.
    #
    # If the mesh admin does not specify a value, Istio will use the value of the
    # mesh's Trust Domain. The best practice is to select a proper Trust Domain
    # value.
    meshID: ""
    # Configure the mesh networks to be used by the Split Horizon EDS.
    #