acknowledgements for ansi/nist-itl 1-2011 - NIST Visual Image ...

ANSI/NIST-ITL 1-2011 - UPDATE 2013 DRAFT VERSIONASCII. Fields from the Type-1 logical record and ASCII Field xx.001 and Field xx.002 textfields shall still be encoded using 7-bit ASCII, but all other designated text fields may beencoded using an alternate character encoding set, if they are shown with the character typeof 'U' or 'user-defined' in the record layout tables at the beginning of each Record TypeSection of this standard. One alternate character encoding set may be chosen per transaction.To switch character encoding sets within a transaction, the Type-1 record shall contain Field1.015 Character encoding / DCS. The DCS consists of 3 information items containing anidentifying code, the name of an international character encoding set, and its version.Retained for backward compatibility is a mechanism using codes to signal the conversion toa different international character encoding set. This mechanism is not recommended for newapplications. However, these codes must be used for UTF-16 or UTF-32 data, since onlyUTF-8 is allowed to be used without the codes. Use of the code requires the ASCII Start-of-Text “ STX ” character (0x02) followed by the equal sign “=” to signal the change to analternate character encoding set defined by the specific DCS code that follows. The entireStart-of-Text sequence is terminated by a single instance of the ASCII End-of-Text “ ETX ”character (0x03). This alternate character encoding set will remain active until a closing“ ETX ” character is encountered or the next ASCII information separator character isencountered. All text between the STX sequence and the closing ETX character shall beencoded in Base-64 notation (See Annex A: Character encoding information). This is trueeven when the 7-bit ASCII character encoding set is specified.Usage of UTF-8 is allowed as an alternative to the technique that requires the usage of theASCII “ STX ” and “ ETX ” characters to signify the beginning or end of international characters.UTF-8 is only allowed in fields marked 'U' or 'user-defined' in the character type column ofthe record layout tables. Notice that this technique does not require the conversion of text toBase-64 as does the technique employing “ STX ” and “ ETX ”.B.2 Encoding for specific record typesThe following sections provide specific detail for for certain fields within the record types toensure clarity to programmers.B.2.1Type-1 recordField 1.001 Record header shall begin with “1.001:” followed by the length of the recordincluding every character of every field contained in the record and the informationseparators. The “ G S” separator character shall separate the length code of Field 1.001 fromthe next field.The year, month, and day values in Field 1.005 Date / DAT are concatenated“YYYYMMDD”.In Field 1.013 Domain name / DOM, the default is “1.013:NORAM U S G S”Immediately following the last information item in the Type-1 record (See Section 8.1), an450