Alpine Real Estate Lawyer, New York

Principles of international law so fundamental that no nation may ignore them or attempt to contract out of them through treaties. For example, genocide and participating in a slave trade are thought to be jus cogens.

A guarantee about the quality of goods or services made by a seller, such as 'This item is guaranteed against defects in construction for one year.' Most express warranties come directly from the manufacturer or are included in the sales contract. If you want to hold the seller to an oral guarantee, it's best to get it in writing or have witnesses to the guarantee so that it doesn't come down to your word against the seller's if a problem arises.

Federal laws that prohibit housing discrimination on the basis of race or color, national origin, religion, sex, familial status or disability. The federal Acts apply to all aspects of the landlord/tenant relationship, from refusing to rent to members of certain groups to providing different services during tenancy.

A provision in a deed or will that attempts to restrict ownership of the property -- for example, selling your house to your daughter with the provision that it never be sold to anyone outside the family. These provisions are generally unenforceable.

A sale of a house in which the proceeds fall short of what the owner still owes on the mortgage. Many lenders will agree to accept the proceeds of a short sale and forgive the rest of what is owed on the mortgage when the owner cannot make the mortgage payments. By accepting a short sale, the lender can avoid a lengthy and costly foreclosure, and the owner is able to pay off the loan for less than what he owes. See also deed in lieu (or foreclosure).

The substitution of a new contract for an old one. A novation may change one of the parties to the contract or the duties that must be performed by the original parties.

A gift of property. The IRS allows you to take an income tax deduction for the value of donations made to charitable organizations who are recognized as such by the IRS.

Any control over property. If you give away property but keep an incident of ownership--for example, you give away an apartment building but retain the right to receive rent--then legally, no gift has been made. This distinction can be important if you're making large gifts to reduce your eventual estate tax.