def construct_policy(mode, name, value='', vtype=''):
    """Map the mode and return a list containing the policy dictionary."""
    default = {'policy_type': 'unknown'}
    policy_map = {'set_reg_value': {'policy_type': 'regpol'},
        'delete_reg_value': {'policy_type': 'regpol', 'action': 'DELETE'},
        'set_secedit_value': {'policy_type': 'secedit'}}
    mapped = policy_map.get(mode, default)
    mapped['key'] = name
    mapped['name'] = name
    mapped['value'] = value
    mapped['vtype'] = vtype
    return [mapped]
