Given a well marked-up XML document, we can format XML elements with XSL, but how are these elements indexed? This paper demonstrates why indexing should be determined per element type rather than the same for all elements. Then I will present a system based on XSLT called XIL for creating “Indexsheets” which is like a stylesheet for indexing. It is a rule-based system based on XPath and part of XSLT. An indexsheet is much like XSL and uses XSLT to identify elements; however, rather than applying formatting with “formatting objects,” indexing rules are applied with “indexing objects.” Since selection of elements is based on XSLT/XPath, the syntax and use is both familiar and standard. XIL also separates structure from indexing attributes as structure is separated from presentation.