HTML Entities, sometimes referred to as named entities, are character entity references used to encode special characters in a markup language such as HTML, SGML, and XML.  The most common use for them is to escape symbols in order to prevent their presence from interfering with the flow of a language parser.  They are also used less frequently when a keyboard or editor does not support entry of a special character that is needed in a document.  HTML entities can also be represented numerically as shown in the Decimal and Hex columns of the reference table.

A practical example of where they are used to escape symbols comes to play when developers interface with BenSelect using Selerix Web Services.  Developers use either SAML or SOAP to exchange communication messages between their server and a BenSelect enrollment server, both of which use XML to package the message request.  Because Selerix requires all data sent to BenSelect to be packaged in a Selerix data transmittal XML envelope, a conflict arises when either SAML or SOAP is used as an envelope for the transmittal XML, since you cannot embed an XML structure within another XML structure.  To get around this, developers convert the transmittal XML to a format that will not interfere with the XML language parser by converting the "less than" [<] and "greater than" [>] symbols into their respective entity codes [&lt;] and [&gt;].  The converted transmittal XML can then be safely included within the body of the carrier message XML.

The table below contains some common HTML Entities that are used frequently to render textual content on the World Wide Web.  Only the first five characters below are recognized XML.  A little thought will make the reason for this clear.

Character	Entity	Decimal	Hex	Rendering
quotation mark	"	"	"	"
ampersand	&	&	&	&
apostrophe	'	'	'	'
less-than sign	&lt;	&#60;	&#x3C;	<
greater-than sign	&gt;	&#62;	&#x3E;	>
inverted exclamation mark	&iexcl;	&#161;	&#xA1;	¡
cent sign	&cent;	&#162;	&#xA2;	¢
pound sign	&pound;	&#163;	&#xA3;	£
currency sign	&curren;	&#164;	&#xA4;	¤
yen sign	&yen;	&#165;	&#xA5;	¥
broken vertical bar	&brvbar;	&#166;	&#xA6;	¦
section sign	&sect;	&#167;	&#xA7;	§
spacing diaeresis - umlaut	&uml;	&#168;	&#xA8;	¨
copyright sign	&copy;	&#169;	&#xA9;	©
feminine ordinal indicator	&ordf;	&#170;	&#xAA;	ª
left double angle quotes	&laquo;	&#171;	&#xAB;	«
not sign	&not;	&#172;	&#xAC;	¬
soft hyphen	&shy;	&#173;	&#xAD;
registered trade mark sign	&reg;	&#174;	&#xAE;	®
spacing macron - overline	&macr;	&#175;	&#xAF;	¯
degree sign	&deg;	&#176;	&#xB0;	°
plus-or-minus sign	&plusmn;	&#177;	&#xB1;	±
superscript two - squared	&sup2;	&#178;	&#xB2;	²
superscript three - cubed	&sup3;	&#179;	&#xB3;	³
acute accent - spacing acute	&acute;	&#180;	&#xB4;	´
micro sign	&micro;	&#181;	&#xB5;	µ
pilcrow sign - paragraph sign	&para;	&#182;	&#xB6;	¶
middle dot - Georgian comma	&middot;	&#183;	&#xB7;	·
spacing cedilla	&cedil;	&#184;	&#xB8;	¸
superscript one	&sup1;	&#185;	&#xB9;	¹
masculine ordinal indicator	&ordm;	&#186;	&#xBA;	º
right double angle quotes	&raquo;	&#187;	&#xBB;	»
fraction one quarter	&frac14;	&#188;	&#xBC;	¼
fraction one half	&frac12;	&#189;	&#xBD;	½
fraction three quarters	&frac34;	&#190;	&#xBE;	¾
inverted question mark	&iquest;	&#191;	&#xBF;	¿
latin capital letter O with slash	&Oslash;	&#216;	&#xD8;	Ø
division sign	&divide;	&#247;	&#xF7;	÷
en dash		&#8211;	&#x2013;	–
em dash		&#8212;	&#x2014;	—
left single quotation mark		&#8216;	&#x2018;	‘
right single quotation mark		&#8217;	&#x2019;	’
single low-9 quotation mark		&#8218;	&#x201A;	‚
left double quotation mark		&#8220;	&#x201C;	“
right double quotation mark		&#8221;	&#x201D;	”
double low-9 quotation mark		&#8222;	&#x201E;	„
dagger		&#8224;	&#x2020;	†
double dagger		&#8225;	&#x2021;	‡
bullet		&#8226;	&#x2022;	•
horizontal ellipsis		&#8230;	&#x2026;	…
per thousand sign		&#8240;	&#x2030;	‰
euro sign	&euro;	&#8364;	&#x20AC;	€
trade mark sign		&#8482;	&#x2122;	™
Latin capital ligature OE	&OElig;	&#338;	&#x152;	Œ
Latin small ligature oe	&oelig;	&#339;	&#x153;	œ
Latin capital letter S with caron	&Scaron;	&#352;	&#x160;	Š
Latin small letter s with caron	&scaron;	&#353;	&#x161;	š
Latin capital letter Y with diaeresis	&Yuml;	&#376;	&#x178;	Ÿ
modifier letter circumflex accent	&circ;	&#710;	&#x2C6;
small tilde	&tilde;	&#732;	&#x2DC;	˜
en space	&ensp;	&#8194;	&#x2002;
em space	&emsp;	&#8195;	&#x2003;
thin space	&thinsp;	&#8201;	&#x2009;
zero width non-joiner	&zwnj;	&#8204;	&#x200C;	‌
zero width joiner	&zwj;	&#8205;	&#x200D;	‍
left-to-right mark	&lrm;	&#8206;	&#x200E;	‎
right-to-left mark	&rlm;	&#8207;	&#x200F;	‏
en dash	&ndash;	&#8211;	&#x2013;	–
em dash	&mdash;	&#8212;	&#x2014;	—
left single quotation mark	&lsquo;	&#8216;	&#x2018;	‘
right single quotation mark	&rsquo;	&#8217;	&#x2019;	’
single low-9 quotation mark	&sbquo;	&#8218;	&#x201A;	‚
left double quotation mark	&ldquo;	&#8220;	&#x201C;	“
right double quotation mark	&rdquo;	&#8221;	&#x201D;	”
double low-9 quotation mark	&bdquo;	&#8222;	&#x201E;	„
dagger	&dagger;	&#8224;	&#x2020;	†
double dagger	&Dagger;	&#8225;	&#x2021;	‡
per mille sign	&permil;	&#8240;	&#x2030;	‰
single left-pointing angle quotation mark	&lsaquo;	&#8249;	&#x2039;	‹
single right-pointing angle quotation mark	&rsaquo;	&#8250;	&#x203A;	›
euro sign	&euro;	&#8364;	&#x20AC;	€