IBM ShopIBM Support Download
HomeNewsProductsservicesSolutionsAbout IBM
Search 
IBM : developerWorks : XML : Education - Online courses

XML Glossary

attribute In XML, a name="value" pair that can be placed in the start tag of an element. The value must be quoted with single or double quotes.
case-sensitive Indicates whether an application, processor, or operating system distinguishes between upper and lower case. If it does, it is case-sensitive. XML tags are case-sensitive, but HTML tags are not.
content model In XML, the expression specifying what elements and data are allowed within an element.
DTD Document Type Definition. In XML, a grammar that describes what tags and attributes are valid in an XML document that refers to the DTD, and in what context the tags and attributes are valid.
EBNF Extended Backus-Naur Form. A formal set of production rules that comprise a grammar defining another language, such as XML.
element In XML, a start tag and its end tag, plus the content between the tags. An empty tag is also an element.
empty declaration In XML, the DTD declaration for an empty tag. For example, if <foo/> is an empty tag, the empty declaration looks like: <!ELEMENT foo EMPTY>.
empty tag In XML, a start and end tag combined in one tag. The tag has a trailing slash, so an XML parser can immediately recognize it as an empty tag and not bother looking for a matching end tag. For example, if foo is an empty tag, it looks like <foo/>.
entity In XML, an entity declaration provides the ability to have constants or replacement dstrings, which are expanded by a pre-processor. An entity declaration maps some token to a replacement string. Later the token can be prefixed with the & character and the replacement string is put in its place.
grammar The syntax of a language. It is expressed formally by a set of production rules, such as the EBNF rules.
valid An XML document is valid if its content conforms to the rules in its DTD.
well-formed An XML document is well-formed if there is one root element, and all its child elements are properly nested within each other. Start tags must have end tags, and each empty tag must be designated as such with a trailing slash. Also all attributes must be quoted, and all entities must be declared.
white-space In XML, characters that are not visible, but used in formatting documents or programs. These characters include the SPACE, TAB, NEWLINE, and CARRIAGE-RETURN characters.



PrivacyLegalContact---