how come only some of the dots on my map have a date as when the book was recieved?Some  just say PBS member and the town/st............others have the members id and the date arrived (but not the town & state).

profile privacy thing???

I think the date would be if they left the book on their bookshelf or took it off.  (That option you choose when you mark a book received.)  Leaving it on your shelf on hold is what causes the system to know a lost posted date.  Some long time members take it off their shelf because for a short time period books would be automatically reposted after about two weeks.  (That was not a success.  That setting did not last long.)  The name, nickname, and town would be due to privacy settings.

When did they add the lines?