Similar to vanilla min-max bounds. Can match exact value, range, at least or at most.

'Between' example:

{
    "min": "1/125",
    "max": "2\""
}

'At least' example:

{
    "min": "1/125"
}

'At most' example:

{
    "max": "1/10"
}

If you need to match exact shutter speed you can set min and max to same value.
Or just skip object definition altogether. i.e. instead of doing this:

{
    "shutter_speed": {
        "min": "1/125",
        "max": "1/125"
    }
}

You can do this:

{
    "shutter_speed": "1/125"
}