Login Credentials Email Template "ResetLink"?

Hi -- In Tessitura, the Example Login Credentials email template has this code:

@if (Model.GetPropertyValue("ResetLink") != null)
{
<p>
<a href="@Model.GetPropertyValue("ResetLink")" target="_blank">Click here to reset your password</a>
</p>
}

Can someone tell me where that property value comes from? 

Searching the tessituranetwork.com site for "ResetLink" yields no results. 

Thanks!

-- Alan