A book was requested from my shelf, I assume the member could not have been on hold at the time of the request. Now details show the book has been out for delivery for days but when I checked the member's profile I saw the account was on hold but no reason was given.

I did use PBS postage so I already have the credit. And yet I'm wondering how this works.  If this member was on vacation hold would the account be marked only 'on hold' or would it be' vacation hold'?

Vacation hold prevents the member from receiving requests, or from getting wish list offers (unless she has the WL book on auto-request, which bypasses vacation hold), but members can still order books while they are on hold.

Some members give themselves a monthly postage budget for mailing books.  Once they've reached the limit, they use the vacation hold option to prevent getting more orders, but may still want to order books.

I think if you are on Vacation Hold, other members can still see your wish list and/or bookshelf.  There will not be any order or post buttons, but the books will show.  The hold mentioned might have been put in place by PBS.  This could have been because the member asked to close their account.  Or because PBS was trying to contact them. 

We can set our lists to private.  Does that show as private or hold?

They could just be on vacation and will mark it received when they get back. Or maybe they just don't want to mail any books out right now.

The account is simply marked as 'on hold' with no bookshelf but there is a WL.

I just clicked on a member's name whose account is on vacation hold.  I can see her profile.  I see the number of books she has posted, and the number of books on her wish list.  When I click on the number of posted books, I don't see any books, but see "This account is currently on hold. When the hold ends, the books will once again become visible" .  When I click on her wish list, I see all her WL books, but there's no "post this book" button.

If a member hasn't set up a profile, I think you'll just be taken to the "This account is on hold..." message. 

If an account has been closed or suspended by the Admin Team, the wording is different.  It will say "This account is currently suspended or closed."  That can be either because a member asked to have their account suspended or closed, or because the Admin Team took action for some reason.

So in your case, given the wording, she either ordered the book while on vacation hold or ordered the book and then placed the vacation hold.  There should be any problems.  A member can mark books received while on hold.

As Patty stated, we do have members who use Vacation Hold to budget their shipping costs.  As well as members actually on vacation. 

My local post office marks books as delivered when they are placed in the hold bin if I hold my mail.

I have my account on hold but I'm not on vacation.  We put our house on the market and I had to pack my books away so we could 'stage' the house.  On the other hand, all of my wishlist books are on auto-request; I come to the site several times a day to read the forums and to mark the books as received when they arrive.

I also put my account on vacation hold when not on vacation.  In fact, it's on vacation hold most of the time, because I just don't want to spend a lot of money on postage when I have more than enough credits.  When they drop below a certain level, I unhold my account and end up shipping out a half dozen books all at once, which lets me pack everything at the same time and also minimizes Post Office trips.