You may never use any script or ornamental font. There are no University-wide rules specifying the fonts you must use.
Some departments do specify the fonts they want students to use.
Please check your department requirements. All type, including super- and subscripts in formulas and footnote indicators, must be large enough and sufficiently dark and crisp to be legible in microfilm. If you have a question about one of your tables or figures, it is a good idea to show us a sample at your earliest convenience. See Section VII.3 for further information about fonts and printers. Special foreign language fonts Be sure to obtain competent technical advice covering every phase of producing your dissertation, from entering text to printing, before you begin using Greek, Russian, Japanese, Hebrew and other non-standard fonts.