Annulets, in architecture, are small square components in the Doric capital, under the quarter-round. They are also called fillets or listels.
An annulet is also a narrow flat moulding, common in other parts of a column, viz. the bases, etc., as well as the capital. It is so called, because it encompasses the column round. In this sense, annulet is frequently used for baguette or little astragal.