What does SQL Server trace flag 253 do?

Question

In another question I was trying to research how to control SQL Server's query plan caches:

http://stackoverflow.com/questions/2593749/is-there-an-equivalent-of-optionrecompile-or-with-recompile-for-an-entire-c

...and I found trace flag 253 via this article:

http://www.sqlservercentral.com/Forums/Topic837613-146-1.aspx

The article is correct, if I run DBCC TRACEON(253) and then a number of queries, I can manually check the query plan cache and see that plans have not been inserted. If I run DBCC TRACEOFF(253), query plans are cached as normal.

So my question is...what else does this flag do? Does anybody know the official story?