bits from the code point are distributed among the UTF-16 bytes. Additional bits added by the UTF-16 encoding process are shown in black. Byte-order encoding schemes UTF-16 and UCS-2 produce a sequence of 16-bit code units. Since most communication and storage protocols are defined for bytes, and each unit thus takes two 8-bit bytes, the order of the bytes may depend on the endianness (byte order) of the computer architecture. To assist in recognizing the byte order of code units, UTF-16 allows a byte order mark (BOM), a code point with the value U+FEFF, to precede the first actual coded value. (U+FEFF is the invisible zero-width non-breaking space/ZWNBSP character.) If the endian architecture of the decoder matches that of the encoder, the decoder detects the 0xFEFF value, but an opposite-endian decoder interprets the BOM as the value U+FFFE reserved for this purpose. This incorrect result provides a hint to perform byte-swapping for the remaining values. If the BOM is missing, RFC 2781 recommends that big-endian (BE) encoding be assumed. In practice, due to Windows using little-endian (LE) order by default, many applications assume little-endian encoding. It is also reliable to detect endianness by looking for null bytes, on the assumption that characters less than U+0100 are very common. If more even bytes (starting at 0) are null, then it is big-endian. The standard also allows the byte order to be stated explicitly by specifying UTF-16BE or UTF-16LE as the encoding type. When the byte order is specified explicitly this way, a BOM is specifically not supposed to be prepended to the text, and a U+FEFF at the beginning should be handled as a ZWNBSP character. Most applications ignore a BOM in all cases despite this rule. For Internet protocols, IANA has approved "UTF-16", "UTF-16BE", and "UTF-16LE" as the names for these encodings (the names are case insensitive). The aliases UTF_16 or UTF16 may be meaningful in some programming languages or software applications, but they are not standard names in Internet protocols. Similar designations, UCS-2BE and UCS-2LE, are used to show versions of UCS-2'''. Size UTF-16 is often claimed to be more space-efficient than UTF-8 for East Asian languages, since it uses two bytes for characters that take 3 bytes in UTF-8. Since real text contains many spaces, numbers, punctuation, markup (for e.g. web pages), and control characters, which take only one byte in UTF-8, this is only true for artificially