Stanford does not have a standard course catalog numbering system. Courses numbered from 1 through 99 are primarily for freshmen and sophomores. Courses numbered from 100 through 199 are primarily for juniors and seniors; some departments, however, offer courses numbered from 200 through 299 for juniors and seniors. Most courses numbered 200 and above are for graduate students; no graduate career course is numbered below 200, and all courses above 300 are for graduate students.