These are part of every title commitment - they are the items that the Title company will not insure if they become a problem regarding the property's title. These are typically recorded with the county or city.
A few examples are recorded oil & gas interests, mechanic's liens, deeds of trust, sometimes city violations against the property from years ago, etc. If you're concerned about these go through them with your real estate attorney to get a plan of action - you can ask the Seller to resolve them but they don't have to, so you can see if they are acceptable or if there is something else you can do to address it.
Hope this helps.