Auction Question - Silent or Secret Reserves?

[ajw]

Hey, I don't post here often, but lurk from time to time. I bid on auction house items rarely and know that many of the readers here are much more experienced than am I. I have a question. Well, three, really. (It's possible I'm using the wrong words, so let me know if the concepts I'm describing have accepted terms.)

First, how common is a "silent reserve" where the description says there is a reserve but does not say what that reserve is?

Second, how common is a "secret reserve" where there is a reserve but the description says nothing about it whatsoever?

Third, what do you think about them? Are they ethical? Would you be less willing to bid if you knew about them (or knew that the auction house used them at times)?

Thanks a bunch for any input you might have...

Drew