The PYLUSD Course Descriptions Catalog gives descriptions of all classes offered in the district; not all courses are offered at YLHS. The YLHS Course Selection Offering list is posted on this site; find a class you are interested in then check out the Course Description Catalog for information about the course. The catalog will tell you the length of the course, grade level the student needs to be in to take the class; and prerequisites. This is a great tool to use during the Course Selection process. PYLUSD Course Catalog.