The documentation for the selector option for popovers and tooltips currently states "if a selector is provided, tooltip objects will be delegated to the specified targets". This description is not very helpful and appears to confuse a good number of people, including myself until I figured out what it actually does (also see #2091).

Explanation: 'selector' is used internally in conjunction with jQuery.on in order to allow markup dynamically inserted in the DOM, to trigger tooltips and popovers. I've created an interactive jsFiddle illustrating its usage: http://jsfiddle.net/KPeKS/4/

tl;dr: selector = jQuery.on support

I therefore propose that the documentation be improved, making note that 'selector' makes the plugins use jQuery.on and a short explanation of what that does, for those who may not be familiar with the function, along with the following sample code:

$('body').tooltip({
    selector: '[rel="tooltip"]'
});

$('body').popover({
    selector: '[rel="popover"]'
});

I'll leave exactly how it might be worded to @mdo / @fat.