A quick update so this doesn't become yet another unanswered ACI question: apparently you need to right-click on the fault and select "Ignore Fault" or "Change Severity." It'll then appear underneath the monitoring policy in use for that tenant or EPG.
To put it into a custom monitoring policy, you need to create a custom monitoring policy either in your tenant or the common tenant (which is where the default tenant monitoring policy is). Apply it to your tenant or the the EPG. Generate a fault; F0467 is easy to generate by trying to statically apply an EPG on an unconfigured interface. Right-click on the fault and select "Ignore Fault" or "Change Severity."
I can't tell you if this actually works to squelch the faults, though, since it looks like there is a bug preventing it from working properly. If you select "Ignore Fault," the fault will disappear from its current location--but new faults will not be squelched. The bug ID is CSCvk00011 and it appears to apply only to 3.2(1m). I'll add that it's annoying to have to generate the fault in order to configure it; there are situations where you would want to do that in advance (i.e., before you do maintanence).
Finally, I couldn't do anything with faults at the fabric level. Right-clicking on a fault like F0532 gives you only the standard ACI object options (save, post, etc.). I'm not sure if this is a design decision, if there is some other procedure required or even some other location where I need to do this.
