switchable

switchable is a predefined attribute set to indicate that an object can be turned on and off. As such, it is often used in conjunction with switchedon.

Example:

object tableLamp "Table lamp"
{
    nouns "lamp", "light"
    adjectives "table", "small", "ugly"

    is switchable,  not switchedon

    long_desc
    {
        "It's the ugly table lamp your mother bought you for Christmas."
        if self is switchedon
            "Currently it is turned on and glowing with a soft white glow."
        else
            "It sits on the table, turned off."
    }
}