In an ongoing series, Google has just announced their most recent search algorithm changes for April 2012. Google is often cryptic when describing their changes, so the exact impact will be clearer over time. From an initial reading, many changes will impact international issues. It also appears there may be even less use of a page’s own title tag for the snippet title (More concise and/or informative titles).
Supplemental index is now called index tiers and there’s a new index tier
In the past Google would label some results as coming from a supplemental index, a type of secondary index. There are pages that Google generally values less and will turn to for results only after searching the primary index. We know now that Google calls secondary indexes “tiers”.
