The symbol indicates a pint. The numbers indicate the date the glass was "tempered". Which is some official Irish thing.
The 06 13 on Guiness glas is the the NSAI "pint" mark which has been used since 2006.
If you mean 06-13-2011 then it is: VI-XIII-MMXI
It means "Expiration date : 06/13", which is 2013 June 30.
06 = vi 13 = xiii 1986 = mcmlxxxvi
Rome - 2012 2013-06-13 was released on: USA: 13 June 2013
The Talk - 2010 2012-06-13 was released on: USA: 13 June 2012
Bandstand - 1952 1960-06-13 was released on: USA: 13 June 1960
The Hour - 2005 2008-06-13 was released on: USA: 13 June 2008
The View - 1997 2008-06-13 was released on: USA: 13 June 2008
The Talk - 2010 2011-06-13 was released on: USA: 13 June 2011
Today - 1952 2013-06-13 was released on: USA: 13 June 2013
Extra - 1994 2013-06-13 was released on: USA: 13 June 2013
About Faces - 1960 1960-06-13 was released on: USA: 13 June 1960