Let say a meta tag for example: <meta name="robots" content="all"> <meta name="revisit-after" content="15 days"> and then later in the <HEAD> was: <meta NAME="robots" CONTENT="FOLLOW,INDEX"> <meta NAME="revisit-asfter" CONTENT="10 days"> It seems someone added tags without carring to remove the originals. This kind of Meta tags are called duplicate Meta Tags.