Step 1: Copy and paste the following code in your master page above the closing head tag and also replace the square bracket with anchor bracket.
[script language="JavaScript"]
_spBodyOnLoadFunctionNames.push("rewriteLinks");
function rewriteLinks() {
var anchors = document.getElementsByTagName("a");
for (var x=0; x
if (anchors[x].outerHTML.indexOf('#newwindow')>0)
{
oldText = anchors[x].outerHTML;
newText = oldText.replace(/#newwindow/,'" target="_blank');
anchors[x].outerHTML = newText;
} } }
[script]
Step 2: If you want selected link to open in a new window just type #newwindow after the url as shown below.