The Division of Graduate, Online & Professional Studies (GPS) runs several computer science courses each summer that are not for CS majors. For a course to count as a CS elective, that course must appear in the regular university catalog. Some courses offered through GPS have 94.xxx course numbers (e.g., 94.308). You may use these to satisfy CS requirements only with prior permission of the CS undergraduate coordinator.
Some GPS courses are not available to CS majors even for general elective credit. Applicable rules are in the CS Policy statement General Electives. For example, computer-oriented Mathematics Dept. courses (which have 92.xxx or 90.xxx course numbers) are hardly ever allowed for CS majors. Please see the undergraduate coordinator if you want a course for non-majors to count for general elective credit.
CS majors may take Winter Intersession courses to satisfy certain General Education and General Elective credits. Please see the undergraduate coordinator before doing so to ensure that you may apply the credits earned to your CS program.