***************************************** * * * ATTRIBUTE SET BIB-1 (Z39.50-1995): * * SEMANTICS * * * ***************************************** September 1995
2.4 STRUCTURE ATTRIBUTES (TYPE = 4) The Structure attribute specifies the type of search term (e.g., a single word, a phrase, several words to be treated as multiple single terms, etc.). The Structure attributes are the following: Structure Value Definition --------------- ----- ------------------------------------------- Phrase 1 A phrase consists of one or more groups of characters separated by blanks (for example, ASCII hex "20"). The value to be searched is exactly as it appears in the search term with respect to order and adjacency. Word(s) in the phrase may be explicitly truncated. (See "Truncation" -- section 2.5 below.) To indicate that additional words may appear in the access point, use the completeness attribute. Word 2 A word consists of a group of non-blank characters. It specifies the exact text of the value to be searched, unless the word is explicitly truncated. (See "Truncation" -- section 2.5 below.) A word search term contains no blanks. Key 3 A key specifies a sequence of characters extracted from those characters contained in an indexed word but not necessarily representing complete words. In the term, key segments should be separated by a blank (ASCII hex "20"). Each key segment should be the length of a key segment in the origin system or the length of the word, to a maximum of 6 characters. (For example, an name/title derived key search term for "Copland, Aaron, 1900- Rodeo" could be "coplan rodeo".) A segment may be adjusted by the target to the length required for the target's indexes. For example, the following derived key searches are in use at LC and at OCLC (in Online System): Site Index Letters taken Source Data ----- ---------- ------------- -------------- OCLC TITLE 3,2,2,1 title keywords NAME/TITLE 4,4 name, title NAME 4,3,1 personal name CNAME 4,3,1 corporate name LC PTK 3,1,1,1 title keywords PATK 3,3 name, title PPNK 5,1 or 6 personal name Year 4 A year search term is numeric and contains four digits. Date 5 The day, month, year and time when a (normalized) transaction or event takes place. The date search term structure is as defined for Generalized Time in ASN.1 (ISO 8824) except that the only mandatory portion of the string is the four-digit representation of the year. Word list 6 A word list consists of one or more words separated by blanks (for example, ASCII hex "20"). No order of the words is implied. The attributes (other than structure) that are associated with the search term apply to each word in the word list. Any words in a word list may be explicitly truncated. (See "Truncation" -- section 2.5 below.) The relationship between the words in a word list is target-specific. Date 100 The day, month, and year when a transaction or (un-normalized) event takes place. The un-normalized search term is unstructured. Name 101 A name search term that is structured in a (normalized) particular order (e.g., last_name, first_name). The resulting term is subject to special matching rules on the target system that differ from those applied to names structured as phrases or unstructured names. Name 102 A name search term that is unstructured (e.g., (un-normalized) first_name last_name), however, the resulting term is subject to matching rules on the target system that differ from those applied to phrases or structured names (e.g., the term "john smith" might be searched by the target as "smith, j#"). Structure 103 The term has a structure that is either implied by the Use attribute or defined by the target. Urx 104 The term is a document identifier, for example, an identifier extracted from a Z39.50 URL. Free-form-text 105 The term is text, input by the end user. May be used, for example, for relevance feedback. Document-text 106 The term is text, extracted from a document. May be used, for example, for relevance feedback. Local-number 107 A number significant to the target. String 108 The entire term is to be treated as a string, rather than a sequence or set of individual words. Numeric string 109 The term is a character string that represents a number.