Silabatta Parāmāsa

What does this fetter really refer to? Is it clinging to rites & rituals and thinking that these practises by their own can lead to liberation OR does it refer to clinging to precepts? If it is the former, then most "rational" inclined people should have little to none of this fetter, no? If it's the latter, then it's NOT about blindly believing a precept, but questioning it and seeing for oneself that it's helpful. However, it appears to me that many rules in the vinyana are there to avoid social faux pax and unnecessary conflicts. If we take the not-eating-after-noon precept, we will see that the Buddha has reason for devising such precept; but do those reasons still hold true nowadays? I doubt it. So if most monks just follow rules and precepts because the Buddha said so (or they are deemed to be effective), then this is called Silabbata Parāmāsa?