local priv_name = "example"
local priv_definition = {
    description = yl_template.t("privs_example_description"),
    -- Privilege description

    give_to_singleplayer = false,
    -- Whether to grant the privilege to singleplayer.

    give_to_admin = true,
    -- Whether to grant the privilege to the server admin.
    -- Uses value of 'give_to_singleplayer' by default.

    on_grant = function(name, granter_name)
        -- logging
        if (type(granter_name) ~= "string") then
            local errormessage = yl_template.t("error_name_not_found",
                                               dump(granter_name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        if not name then
            local errormessage = yl_template.t("error_name_not_found",
                                               dump(name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        if not priv_name then
            local errormessage = yl_template.t("error_priv_not_found",
                                               dump(priv_name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        local text = yl_template.t("privs_example_grant_logmessage",
                                   dump(granter_name), dump(priv_name),
                                   dump(name))
        yl_template.log(text)
    end,
    -- Called when given to player 'name' by 'granter_name'.
    -- 'granter_name' will be nil if the priv was granted by a mod.

    on_revoke = function(name, revoker_name)
        -- logging
        if (type(revoker_name) ~= "string") then
            local errormessage = yl_template.t("error_name_not_found",
                                               dump(revoker_name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        if not name then
            local errormessage = yl_template.t("error_name_not_found",
                                               dump(name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        if not priv_name then
            local errormessage = yl_template.t("error_priv_not_found",
                                               dump(priv_name))
            yl_template.log(errormessage)
            return false, errormessage
        end
        local text = yl_template.t("privs_example_revoke_logmessage",
                                   dump(revoker_name), dump(priv_name),
                                   dump(name))
        yl_template.log(text)
    end
    -- Called when taken from player 'name' by 'revoker_name'.
    -- 'revoker_name' will be nil if the priv was revoked by a mod.

    -- Note that the above two callbacks will be called twice if a player is
    -- responsible, once with the player name, and then with a nil player
    -- name.
    -- Return true in the above callbacks to stop register_on_priv_grant or
    -- revoke being called.
}

minetest.register_privilege(priv_name, priv_definition)