Many library catalogue systems allow variations of these search delimiters embodied in a standard called Z39.50. Presently, wais is being phased out in favor of easier to use web-based search engines. Wais really was designed for an earlier generation of machines in the late 1980s, even though it showed the way for today's comparatively sophisticated search engines. Yahoo is popular, having its start as a Stanford University student project. Initially, contents were of high interest to the college audience but it has broadened recently since it went commercial with advertiser support.
Boolean logic allows multiple key words to be used, joined by a logical operator.
Try Yahoo's boolean capabilities . This is often the case. Of course, compounds can be made. Unfortunately, the nomenclature of searching is not standardized, so you have to check the description for each search engine to see how its action can be controlled. This comes close to the kind of control experienced with the UW libraries' catalogue system , Willow.