The ASCII (7-bit) (American National Standard Code for Information Interchange) code set is defined in ANSI Spec X3.4. Extended (8-bit codes), as defined in ISO8859-1, (Latin 1) can also be used in HTML.
Text data: ASCII
See also: Special Character Names
Character Usage
There are two main codes in use for
character data: ASCII and EBCDIC. EBCDIC is used almost exclusively on IBM
machines and their clones. On most other computer systems,
, ASCII is used, so that is all we will discuss here.
ASCII is by far the more common of the two.
ASCII stands for American Standard Code for Information Interchange. It
contains a binary code for all the characters generated by the keyboard, and
a few others that are not generated by all keyboards.
The standard ASCII set consists of 128 binary codes, from 000 0000 to 111
1111. The msb of the byte is not written because it is sometimes reserved
for a parity bit (an error check: see later) and on some micro computers
another 128 special symbols (graphic characters or mathematical symbols) are
defined using this eighth bit. Since its use varies from one system to
another, we will explicitly write only the first 7 bits.
HTML Character References use the Decimal code. e.g. @ = '@' .
URL Encoding uses Hex characters (e.g. %40 = @)
CTRL (^D means to hold the CTRL key and hit d)
Oct Dec Char Hex Key Comments
\000 0 NUL \x00 ^@ \0 (Null byte)
\001 1 SOH \x01 ^A (Start of heading)
\002 2 STX \x02 ^B (Start of text)
\003 3 ETX \x03 ^C (End of text) (see: UNIX keyboard CTRL)
\004 4 EOT \x04 ^D (End of transmission) (see: UNIX keyboard CTRL)
\005 5 ENQ \x05 ^E (Enquiry)
\006 6 ACK \x06 ^F (Acknowledge)
\007 7 BEL \x07 ^G (Ring terminal bell)
\010 8 BS \x08 ^H \b (Backspace) (\b matches backspace inside [] only)
(see: UNIX keyboard CTRL)
\011 9 HT \x09 ^I \t (Horizontal tab)
\012 10 LF \x0A ^J \n (Line feed) (Default UNIX NL) (see End of Line below)
\013 11 VT \x0B ^K (Vertical tab)
\014 12 FF \x0C ^L \f (Form feed)
\015 13 CR \x0D ^M \r (Carriage return) (see: End of Line below)
\016 14 SO \x0E ^N (Shift out)
\017 15 SI \x0F ^O (Shift in)
\020 16 DLE \x10 ^P (Data link escape)
\021 17 DC1 \x11 ^Q (Device control 1) (XON) (Default UNIX START char.)
\022 18 DC2 \x12 ^R (Device control 2)
\023 19 DC3 \x13 ^S (Device control 3) (XOFF) (Default UNIX STOP char.)
\024 20 DC4 \x14 ^T (Device control 4)
\025 21 NAK \x15 ^U (Negative acknowledge) (see: UNIX keyboard CTRL)
\026 22 SYN \x16 ^V (Synchronous idle)
\027 23 ETB \x17 ^W (End of transmission block)
\030 24 CAN \x18 ^X (Cancel)
\031 25 EM \x19 ^Y (End of medium)
\032 26 SUB \x1A ^Z (Substitute character)
\033 27 ESC \x1B ^[ (Escape)
\034 28 FS \x1C ^\ (File separator, Information separator four)
\035 29 GS \x1D ^] (Group separator, Information separator three)
\036 30 RS \x1E ^^ (Record separator, Information separator two)
\037 31 US \x1F ^_ (Unit separator, Information separator one)
\177 127 DEL \x7F ^? (Delete) (see: UNIX keyboard CTRL)
(See: Special Character Names)
\040 32 " " \x20 (space)
\041 33 ! \x21 EXCLAMATION POINT(bang)
\042 34 " \x22 QUOTATION MARK, DIAERESIS
\043 35 # \x23: NUMBER SIGN (Pound sign) (see: UNIX keyboard CTRL)
\044 36 $ \x24 DOLLAR SIGN
\045 37 % \x25 PERCENT SIGN
\046 38 & \x26 AMPERSAND
\047 39 ' \x27 APOSTROPHE, RIGHT SINGLE QUOTATION MARK, ACUTE ACCENT (single quote)
\050 40 ( \x28 LEFT PARENTHESIS (open parenthesis)
\051 41 ) \x29 RIGHT PARENTHESIS (close parenthesis)
\052 42 * \x2A ASTERISK
\053 43 + \x2B PLUS SIGN
\054 44 , \x2C COMMA, CEDILLA
\055 45 - \x2D HYPHEN, MINUS SIGN
\056 46 . \x2E PERIOD, DECIMAL POINT, (Full Stop)
\057 47 / \x2F SLANT (SOLIDUS), slash
\060 48 0 \x30 \061 49 1 \x31 \062 50 2 \x32 \063 51 3 \x33 \064 52 4 \x34 \065 53 5 \x35 \066 54 6 \x36 \067 55 7 \x37 \070 56 8 \x38 \071 57 9 \x39
\072 58 : \x3A COLON \073 59 ; \x3B SEMICOLON \074 60 < \x3C LESS-THAN SIGN (left angle bracket) \075 61 = \x3D EQUALS SIGN \076 62 > \x3E GREATER-THAN SIGN (right angle bracket) \077 63 ? \x3F QUESTION MARK \100 64 @ \x40 COMMERCIAL AT † (see: UNIX keyboard CTRL)
\101 65 A \x41 \112 74 J \x4A \123 83 S \x53 \102 66 B \x42 \113 75 K \x4B \124 84 T \x54 \103 67 C \x43 \114 76 L \x4C \125 85 U \x55 \104 68 D \x44 \115 77 M \x4D \126 86 V \x56 \105 69 E \x45 \116 78 N \x4E \127 87 W \x57 \106 70 F \x46 \117 79 O \x4F \130 88 X \x58 \107 71 G \x47 \120 80 P \x50 \131 89 Y \x59 \110 72 H \x48 \121 81 Q \x51 \132 90 Z \x5A \111 73 I \x49 \122 82 R \x52
\133 91 [ \x5B LEFT (SQUARE) BRACKET (open bracket) † \134 92 \ \x5C REVERSE SLANT (REVERSE SOLIDUS) (backslash, backslant) † \135 93 ] \x5D RIGHT (SQUARE) BRACKET (closing bracket) † \136 94 ^ \x5E CIRCUMFLEX ACCENT † \137 95 _ \x5F UNDERLINE (LOW LINE) \140 96 ` \x60 LEFT SINGLE QUOTATION MARK, GRAVE ACCENT †
\141 97 a \x61 \152 106 j \x6A \163 115 s \x73 \142 98 b \x62 \153 107 k \x6B \164 116 t \x74 \143 99 c \x63 \154 108 l \x6C \165 117 u \x75 \144 100 d \x64 \155 109 m \x6D \166 118 v \x76 \145 101 e \x65 \156 110 n \x6E \167 119 w \x77 \146 102 f \x66 \157 111 o \x6F \170 120 x \x78 \147 103 g \x67 \160 112 p \x70 \171 121 y \x79 \150 104 h \x68 \161 113 q \x71 \172 122 z \x7A \151 105 i \x69 \162 114 r \x72
\173 123 { \x7B LEFT BRACE (LEFT CURLY BRACKET) (open brace) †
\174 124 | \x7C VERTICAL LINE (pipe) †
\175 125 } \x7D RIGHT BRACE (RIGHT CURLY BRACKET) (closing brace) †
\176 126 ~ \x7E TILDE (OVERLINE) (squiggle) †
\177 127 DEL \x7F ^? (Delete) (see: UNIX keyboard CTRL) † The characters following the letters may be used for additional letters in countries with alphabets containing more than 26 letters.These characters should not bae used in international interchange without determining that there is agreement between sender and recipient.
End of Line character
End of Line varies depending on the operating system: DOS/Windows: <CR><LF> Macintosh:... <CR> UNIX..........<LF> (See File Format Notes for more information.)UNIX Keyboard Control Characters
: The default keyboard control characters vary depending on the UNIX system. Most people change them with the stty command in their .profile. SysV Sun/Solaris HP/UX Erase (character delete) # <DEL> <BS> (^H) Kill (line delete) @ ^U @ Intr (Interupt process) <DEL> ^C <DEL> EOF (End of File) ^D ^D ^D EOF Signals End of File for characters input from the terminal. Also causes shell to terminate.
Note: The only characters other than letters and digits which appear to
be universly acceptable are - (dash) and _ (underscore) and you
have to watch out for '-' which can be interpreted as minus when
used in a name in certain perl scripts.
(1) (2) (3)
Octal UNIX DOS SMTP URL (HTML - allows all but <, >, &,and ")
\011 TAB
\040 " " - Spaces can be used in mail addresses if the addr. is quoted.
\041 ! * * * ! can cause problems in csh in UNIX.
\042 "
\043 # * * * (see: UNIX keyboard CTRL)
\044 $ * * *
\045 % * * *
\046 & * *
\047 ' * * *
\050 ( *
\051 ) *
\052 * * *
\053 + * * * (URL's sometimes use + for space)
\054 , *
\055 - * * * *
\056 . *
\057 / *
\072 : *
\073 ;
\074 <
\075 = * *
\076 >
\077 ? *
\100 @ * * (see: UNIX keyboard CTRL)
\133 [
\134 \
\135 ]
\136 ^ * *
\137 _ * * * *
\140 ` * *
\173 { * *
\174 | *
\175 } * *
\176 ~ * * *
(1) UNIX - Any character except "/" (slash) is allowed
in a UNIX file name but many are not recommended
because they cause problems in scripting and/or
programming languaages dealing with the files.
(2) SMTP - (Simple Mail Transfer Protocol)
(3)URI/URL - Uniform Resource Identifier/Locator. Other characters can
be used but require encoding with % and the HEX value (e.g. @ = %40)
(Space is sometimes encoded as "+".)
(4) HTML - HyperText Markup Language requires 4 ASCII characters to be
encoded as character or entity references (escape sequences).
ASCII characters with special meaning in HTML so they must be encoded:
Character Entity
Character Reference Reference
< < <
> > >
& & &
" " "
Other common non-ASCII character encodings for HTML:
Description Code Entity name Octal Code
e, acute accent é --> é é --> é \351 (octal) = é
ampersand & --> & & --> &
registered trademark ® --> ® ® --> ®
copyright © --> © © --> ©
trademark ™ --> ™ <SUP><FONT SIZE=-1>TM</FONT></SUP> --> TM
ISO8859-1, (Latin 1) notes and Character List at Best Business Solutions (BBS).
Extended ASCII (same as ISO859-1) at emory.edu
ISO (International Organization for Standardization) defines several character sets.
e.g. the ISO 8859 series.
HTML Character Entity names are defined targnet.org and uni-passau.
IBM
IBM uses (EBCDIC) Extended Binary Coded Decimal Interchange Code
(8-bit) coding on most of their systems.
They uses code pages to specify charact sets for keyboards, displays,
printers, ... for DOS, AIX, Mainframes, ....
Standard DOS code pages are:
437 United States
850 Multilingual (Latin 1)
852 Slavic (Latin 2)
863 Canadian-French
865 Nordic (Norwegian, Danish)
860 Portuguese
See:
IBM OS/390 Code Pages
General Info. on Code Pages
See also: BYTE article 'Organizing Babylon' on international character sets.
Netscape Character Sets
MIME Charset parameter in HTTP. If the server includes this parameter in its
response, Netscape Navigator will change its character set appropriately.
For example:
Content-Type: text/html;charset=iso-8859-1
Content-Type: text/html;charset=iso-2022-jp
The charset names recognized by Netscape Navigator 1.1 are specified in
RFC 1700 (except for the names that begin with "x-".) These include:
us-ascii
iso-8859-1
iso-2022-jp
x-sjis
x-euc-jp
x-mac-roman
Additionally, the following aliases are recognized for us-ascii:
ansi_x3.4-1968
iso-ir-6
ansi_x3.4-1986
iso_646.irv:1991
ascii
iso646-us
us
ibm367
cp367
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