"Free and Clear"

What is "Free & Clear", with the exception of an IRS lien which could still be in place will have to be paid by the buyer to clear title.A tax lien will cancel private liens,but not all liens will be canceled in California.(http://ttc.lacounty.gov/proptax/docs/TermsAndCondition.pdf).These can be found as public record,as investors we like equity,so be careful about free and clear they may not be free and clear(due diligence).