1) could the search be applied to particular sub-sections of the website. If a visitor navigates to any of the sub-sections, their search by default will be filtered on the subsection that the page they are on is in, if they wish however they should extend the search to the whole site or other subsections.
2) Search should also include the contents in the pdf files
3) Can the users be able to specify operators to allow them to refine search criteria further, e.g. +, -, OR, AND, NOT, "", etc.
4) Can the search include Best Bets functionality
5) After performing a search it will be possible to refine the search by performing a "search within these results"