Rel is a program that determines the relevance of text documents to a set of keywords expressed in boolean infix notation. The list of file names that are relevant are printed to the standard output, in order of relevance. The boolean logical operators supported are, "&" for logical "and," "|" for logical "or," and "!" for logical "not." Parenthesis are used as grouping operators.

The forward relationship also known as the "link type". It specifies a named relationship from the enclosing document to the resource specified by the HREF attribute. HTML link relationships are as yet unstandardized, although some conventions have been established. Here are some proposed/used relationship values: Value Description

A relation, i.e. a logical predicate, of an atom (Atom). It is optionally surrounded by an operator (op). Attributes: @uri(See: atom module)

3.2|] [ X1| X1.1] [ IE3B1| M3| N4B2| O3.5] Standards Details: In all HTML 4.x/XHTML DTDs Required? No Description: The REL attribute is meant to give the relationship(s) described between the current document and the document specified by the HREF attribute. Values: A whitespace separated list of relationship names.

This attribute names a relationship between the linked document and the current document. Possible values for this attribute include alternate, bookmark, chapter, contents, copyright, glossary, help, , next, prev, section, start, stylesheet, and subsection. The most common use of this attribute is to specify a link to an external style sheet. The rel attribute is set to stylesheet, and the href attribute is set to the URL of an external style sheet to format the page. WebTV also supports the use of the value next for rel to preload the next page in a document series.