Seems like I'm on a "roll" here for post. This job I'm on is bringing up a lot of questions. I always hear that the ditch for UF cable is 18", but from what I see in Table 300.5, unless it's under one of the special conditions in the table ( concrete etc.), it is 24". Everybody I've ever heard just about, says it's 18". A customer just told me one of the DIY books said 18". Am I missing something here. I've heard this all my years in electrical work, but as I read the code, regular underground depth is 24". Thanks again.