In addition to the contents, users can query properties stored on objects. Since a Word document or any OLE compound document can have properties associated with it, these can be searched for. For example, a user could search a server for all documents he or she wrote, if the location of that document had been forgotten. Similarly, a user who knew the author of a paper, but not its title, could search for papers written by that author.
In addition to author, indexed properties include data such as file size, creation and modification dates, and file names. Clients can query both textual properties, such as the file name or author, and numerical properties, such as the size or time of the last modification. All OLE properties can be queried, including custom properties in Microsoft Office documents.
The standard comparison operators are legal. These include =, >, <, >=, <=, and != (not equal) for numeric and textual properties. In addition, for textual properties all the content query functionality is available. Initially, properties can only be compared to constants; comparing one property to another is not available. Query restriction terms may be freely mixed using Boolean operators (AND, OR and AND NOT) and parentheses.