def define_options(enable=[], disable=[]):
    """
    Define the options for the subscribed events.
    Valid options:
        - CRfile: file created
        - CRdir: directory created
        - MDfile: file modified
        - MDdir: directory modified
        - MVfile: file moved
        - MVdir: directory moved
        - DLfile: file deleted
        - DLdir: directory deleted
        - all: for disable only. Disables all options.
    By default all options are enabled.
    If all options are disabled, 'enable' options are applied.
    If all options are not disabled, 'disable' options are disabled.
    """
    default_options = [
        'CRfile', 'CRdir', 'MDfile', 'MDdir',
        'MVfile', 'MVdir', 'DLfile', 'DLdir'
    ]
    if disable == enable == []:
        return default_options
    elif 'all' in disable:
        return list(set(enable) & set(default_options))
    else:
        return list(set(default_options) - set(disable))