6.1800 [6.033] began enforcing the 6.1910 [6.004] prerequisite last year. Because this is still somewhat new, we may make some exceptions for students in special circumstances. If you have not taken 6.1910 yet, but feel that you have a compelling reason to take 6.1800 anyway (e.g., you're graduating this semester and your degree requires 6.1800, you completed almost all of 6.1910 but needed to OX it, etc.), please fill out this form. You can expect a response within 3-4 business days.