http://stackoverflow.com/a/8867079

Using target=”_blank” will instruct the browser to create a new browser tab or window when the user clicks on the link.

Using target=”_new” is technically invalid according to the specifications, but as far as I know every browser will behave the same way:

Note target=”_new” will behave exactly the same as target=”new”, and the latter is valid HTML while the former is invalid HTML.

Adding some confusion to this, in HTML4 the target attribute was deprecated. In HTML5 this decision was reversed, and it is an official part of the spec once again. All browsers support target no matter what version of HTML you are using, but some validators will flag the use as deprecated if your doctype is HTML4.


http://www.w3.org/TR/html4/types.html#type-frame-target

The following target names are reserved and have special meanings.