How do you find out when a tentative site has been removed from the UNESCO website
I presume you mean "removed but not inscribed
" rather than "inscribed but not removed from T List for some time thereafter
" (some "never" seem to get removed - https://www.worldheritagesite.org/connection/Already+inscribed%2C+still+on+T+List
) - though the approach I use would work for either. You would just have to do more "trial and error" for the latter case.
It helps to know approximately when a country has updated its T List in order to avoid a lot of "trial and error". Some countries do major periodic changes and they are easier to trace than ones which do "bit changes"
a. Go to Wayback machine and get to the T List crawl history of the country whose former T List site you are interested in .
E.g UK - https://web.archive.org/web/20120228141827/http://whc.unesco.org/en/tentativelists/st ate=gb
b. Lets try to find when "Shakespeare's Stratford" was removed (in fact we know from worldheritagesite.org that it was some time in 2012!).
c. Wayback machine shows crawls from 2005. If I choose 2011 there was a crawl on 4 Dec 2011. That shows "Shakespeare's Stratford" still "officially" on UK's T List - https://web.archive.org/web/20111204051151/http://whc.unesco.org/en/tentativelists/st ate=gb
d. If I go to the crawls on 3 and 26 Jan 2012 it is still there. But the crawl of 28 Feb shows it is missing - hardly surprising as we know that UK updated its T List on 27 Jan so it must have been removed at that time - https://web.archive.org/web/20120228141827/http://whc.unesco.org/en/tentativelists/st ate=gb
A similar approach can obviously be used to discover when elements might have been added to or removed from T List definitions. I will not of course work if the removal was prior to the web archive being created. UNESCO didn't get its detailed record of T Lists onto its Web site until around June 2006 - so the only source I know of before then is the WHC and Bureau papers. These are what we used to gather the information on this site. It is a lot more time consuming and the dates of removal often have to be "presumed" . The links to the relevant document among each year's WHC/Bureau papers can be found somewhere (!!) among the posts on this Forum. I can find them if you want them. They go back to the early 1980s.