STAS ATTRIBUTE SEMANTICS This Attachment provides some general guidelines for the use and support of STAS Attributes. Use Attributes (type=1) Terms may have multiple Use Attributes. The indices are logically ORed together. Relation Attributes (type=2) Relation Attributes can be specified on any term. However, there are some restrictions: 1. Only one Relation Attribute is permitted per term. 2. If a Truncation Attribute other than "do not truncate" is specified, the Relation Attribute must be "equal" (value = 3). 3. Relation Attributes are not allowed on Result Set terms. STAS supports the _BIB-1_ Realtion attributes. Truncation Attributes (type=5) Only one Truncation Attribute can be specified per term. Regular expressions can be used to specify left truncation, right truncation, or single character substitution. The regular expressions for truncation may be repeated, and may appear in any order. STAS supports the _BIB-1_ Truncation attributes. Completeness Attribute (type=6) If the value of the Completeness Attribute is 2000, both singular and PLURAL forms of the term are used for searching. STAS suppports the _BIB-1_ Completeness attributes. STAS Search Crossover Attributes (type=2002) The STAS Search Crossover Attribute type applies only to files with appropriate index structures, allowing crossover searching.