Haven

A haven is a place of safety; a refuge or sanctuary.

Examples of havens include the following:
 * A data haven is a refuge for uninterrupted or unregulated data;
 * A tax haven is a state, country or territory where certain taxes are levied at a low rate or not at all;
 * A corporate haven is a jurisdiction with laws friendly to corporations thereby encouraging them to choose that jurisdiction as a legal domicile.

The concept of a haven was utilized by Liquid Ocelot for his "Outer Haven," based on the original Outer Heaven, and also used as the name of his warship.

Unconfirmed name usage
"Haven" was the name of the island on which Meryl Silverburgh and Johnny Sasaki married, as well as the place in which Sunny met her first outdoor friend. The island was a place where corporations went to avoid paying national taxes and located servers to ensure the physical safety of data that they didn't intend to have in their own countries. A population of a few thousand made up of these corporations, and was small enough to be considered a nation in name only.

Behind the scenes
The Project Itoh novelization for Metal Gear Solid 4: Guns of the Patriots, names the island, on which Meryl Silverburgh and Johnny Sasaki marry, as "Haven." The location appears in the first part of the epilogue Naked Sin but is never named in the game itself.