Decimal floating point (3 or 4 binary bits), and the rest of the significand uses the densely packed decimal (DPD) encoding. Unlike the binary integer significand version, where the exponent changed position and came before the significand, this encoding combines the leading 2 bits of the exponent and the leading digit (3 or 4 bits) of the significand into the five bits that follow the sign bit. This is followed by a fixed-offset exponent continuation field. Finally, the significand continuation field made of 2, 5, or 11 10-bit "declets", each encoding 3 decimal digits. If the first two bits after the sign bit
Universal Decimal Classification to enable mechanical sorting and filing of subjects. UDC uses Arabic numerals arranged decimally. Every number is thought of as a decimal fraction with the initial decimal point omitted, which determines the filing order. An advantage of decimal notational systems is that they are infinitely extensible, and when new subdivisions are introduced, they need not disturb the existing allocation of numbers. For ease of reading, a UDC notation is usually punctuated after every third digit: In UDC the notation has two features that make the scheme easier to browse and work with: UDC is an analytico-synthetic and faceted classification. It