At-death transfers are classified as follows:
(a) A specific gift is a transfer of specifically identifiable property.
(b) A general gift is a transfer from the general assets of the transferor that does not give specific property.
(c) A demonstrative gift is a general gift that specifies the fund or property from which the transfer is primarily to be made.
(d) A general pecuniary gift is a pecuniary gift within the meaning of Section 21118.
(e) An annuity is a general pecuniary gift that is payable periodically.
(f) A residuary gift is a transfer of property that remains after all specific and general gifts have been satisfied.