Byte Order Mark
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Byte Order Mark
The byte order mark (BOM) is a particular usage of the special Unicode character, , whose appearance as a magic number at the start of a text stream can signal several things to a program reading the text: * The byte order, or endianness, of the text stream in the cases of 16-bit and 32-bit encodings; * The fact that the text stream's encoding is Unicode, to a high level of confidence; * Which Unicode character encoding is used. BOM use is optional. Its presence interferes with the use of UTF-8 by software that does not expect non-ASCII bytes at the start of a file but that could otherwise handle the text stream. Unicode can be encoded in units of 8-bit, 16-bit, or 32-bit integers. For the 16- and 32-bit representations, a computer receiving text from arbitrary sources needs to know which byte order the integers are encoded in. The BOM is encoded in the same scheme as the rest of the document and becomes a Unicode code point if its bytes are swapped. Hence, the process access ...
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Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expressed in most of the world's writing systems. The standard, which is maintained by the Unicode Consortium, defines as of the current version (15.0) 149,186 characters covering 161 modern and historic script (Unicode), scripts, as well as symbols, emoji (including in colors), and non-visual control and formatting codes. Unicode's success at unifying character sets has led to its widespread and predominant use in the internationalization and localization of computer software. The standard has been implemented in many recent technologies, including modern operating systems, XML, and most modern programming languages. The Unicode character repertoire is synchronized with Universal Coded Character Set, ISO/IEC 10646, each being code-for-code id ...
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Notepad (Windows)
Windows Notepad is a simple text editor for Windows; it creates and edits plain text documents. First released in 1983 to commercialize the computer mouse in MS-DOS, Notepad has been part of every version of Windows ever since. History In May 1983, at the COMDEX computer expo in Atlanta, Microsoft introduced the Multi-Tool Notepad, a mouse-based text editor Richard Brodie had created, along with the $195 Microsoft Mouse. Also appearing at that COMDEX was the Multi-Tool Word, a word processor that Charles Simonyi was developing and supported the mouse. Most visitors had never heard of a computer mouse before. The mouse began shipping in July. Initial sales were modest because it had no use other than running the programs included in the box (a tutorial, a practice app, and Multi-Tool Notepad.) The Multi-Tool product line began with expert systems for the Multiplan spreadsheet. On the suggestion of Rowland Hanson, Microsoft dropped the Multi-Tool brand name. Hanson's rationale ...
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CP1252
Windows-1252 or CP-1252 (code page 1252) is a single-byte character encoding of the Latin alphabet, used by default in the legacy components of Microsoft Windows for English and many European languages including Spanish, French, and German. It is the most-used single-byte character encoding in the world (on websites at least). , 0.3% of all websites declared use of Windows-1252, but at the same time 1.3% used ISO 8859-1 (while only 8 of the top 1000 websites), which by HTML5 standards should be considered the same encoding, so that 1.6% of websites effectively use Windows-1252. Pages declared as US-ASCII would also count as this character set. An unknown (but probably large) subset of other pages use only the ASCII portion of UTF-8, or only the codes matching Windows-1252 from their declared character set, and could also be counted. Depending on the country, use can be much higher than the global average, e.g., for Brazil according to website use (including ISO-8859-1), use ...
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UTF-32
UTF-32 (32-bit Unicode transformation format, Unicode Transformation Format) is a fixed-length Character encoding, encoding used to encode Unicode code points that uses exactly 32 bits (four bytes) per code point (but a number of leading bits must be zero as there are far fewer than 232 Unicode code points, needing actually only 21 bits). UTF-32 is a fixed-length encoding, in contrast to all other Unicode transformation formats, which are variable-length encodings. Each 32-bit value in UTF-32 represents one Unicode code point and is exactly equal to that code point's numerical value. The main advantage of UTF-32 is that the Unicode code points are directly indexed. Finding the ''Nth'' code point in a sequence of code points is a constant time, constant-time operation. In contrast, a variable-length code requires linear time, linear-time to count ''N'' code points from the start of the string. This makes UTF-32 a simple replacement in code that uses integers that are incremented by o ...
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Comparison Of Web Browser Engines (HTML Support)
This article compares browser engines, especially actively- developed ones. Some of these engines have shared origins. For example, the WebKit engine was created by forking the KHTML engine in 2001. Then, in 2013, a modified version of WebKit was officially forked as the Blink engine. General information Support These tables summarize what actively-developed engines can support. Operating systems The operating systems that engines can run on without emulation. Image formats Media formats Typography Other items See also *Comparison of web browsers *Comparison of email clients Notes References {{Browser engines Layout engines engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...
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Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet Protocol-related symbols and Internet numbers. Currently it is a function of ICANN, a nonprofit private American corporation established in 1998 primarily for this purpose under a United States Department of Commerce contract. ICANN managed IANA directly from 1998 through 2016, when it was transferred to Public Technical Identifiers (PTI), an affiliate of ICANN that operates IANA today. Before it, IANA was administered principally by Jon Postel at the Information Sciences Institute (ISI) of the University of Southern California (USC) situated at Marina Del Rey (Los Angeles), under a contract USC/ISI had with the United States Department of Defense. In addition, five regional Internet registries delegate number resources to their custo ...
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Little-endian
In computing, endianness, also known as byte sex, is the order or sequence of bytes of a word of digital data in computer memory. Endianness is primarily expressed as big-endian (BE) or little-endian (LE). A big-endian system stores the most significant byte of a word at the smallest memory address and the least significant byte at the largest. A little-endian system, in contrast, stores the least-significant byte at the smallest address. Bi-endianness is a feature supported by numerous computer architectures that feature switchable endianness in data fetches and stores or for instruction fetches. Other orderings are generically called middle-endian or mixed-endian. Endianness may also be used to describe the order in which the bits are transmitted over a communication channel, e.g., big-endian in a communications channel transmits the most significant bits first. Bit-endianness is seldom used in other contexts. Etymology Danny Cohen introduced the terms ''big-endian' ...
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Big-endian
In computing, endianness, also known as byte sex, is the order or sequence of bytes of a word of digital data in computer memory. Endianness is primarily expressed as big-endian (BE) or little-endian (LE). A big-endian system stores the most significant byte of a word at the smallest memory address and the least significant byte at the largest. A little-endian system, in contrast, stores the least-significant byte at the smallest address. Bi-endianness is a feature supported by numerous computer architectures that feature switchable endianness in data fetches and stores or for instruction fetches. Other orderings are generically called middle-endian or mixed-endian. Endianness may also be used to describe the order in which the bits are transmitted over a communication channel, e.g., big-endian in a communications channel transmits the most significant bits first. Bit-endianness is seldom used in other contexts. Etymology Danny Cohen introduced the terms ''big-endian'' a ...
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Specials (Unicode Block)
Specials is a short Unicode block of characters allocated at the very end of the Basic Multilingual Plane, at U+FFF0–FFFF. Of these 16 code points, five have been assigned since Unicode 3.0: *, marks start of annotated text *, marks start of annotating character(s) *, marks end of annotation block *, placeholder in the text for another unspecified object, for example in a compound document. * used to replace an unknown, unrecognized, or unrepresentable character * not a character. * not a character. FFFE and FFFF are not unassigned in the usual sense, but guaranteed not to be Unicode characters at all. They can be used to guess a text's encoding scheme, since any text containing these is by definition not a correctly encoded Unicode text. Unicode's character can be inserted at the beginning of a Unicode text to signal its endianness: a program reading such a text and encountering 0xFFFE would then know that it should switch the byte order for all the following characters. ...
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Character Encoding
Character encoding is the process of assigning numbers to Graphics, graphical character (computing), characters, especially the written characters of Language, human language, allowing them to be Data storage, stored, Data communication, transmitted, and Computing, transformed using Digital electronics, digital computers. The numerical values that make up a character encoding are known as "code points" and collectively comprise a "code space", a "code page", or a "Character Map (Windows), character map". Early character codes associated with the optical or electrical Telegraphy, telegraph could only represent a subset of the characters used in written languages, sometimes restricted to Letter case, upper case letters, Numeral system, numerals and some punctuation only. The low cost of digital representation of data in modern computer systems allows more elaborate character codes (such as Unicode) which represent most of the characters used in many written languages. Character enc ...
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UTF-16
UTF-16 (16-bit computing, 16-bit Unicode Transformation Format) is a character encoding capable of encoding all 1,112,064 valid code points of Unicode (in fact this number of code points is dictated by the design of UTF-16). The encoding is variable-width encoding, variable-length, as code points are encoded with one or two 16-bit ''code units''. UTF-16 arose from an earlier obsolete fixed-width 16-bit encoding, now known as UCS-2 (for 2-byte Universal Character Set), once it became clear that more than 216 (65,536) code points were needed. UTF-16 is used by systems such as the Microsoft Windows API, the Java programming language and JavaScript/ECMAScript. It is also sometimes used for plain text and word-processing data files on Microsoft Windows. It is rarely used for files on Unix-like systems. 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 s ...
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