Creating a new website today, I chose "<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">" but I have no reason why. I just picked it.
Will the DocType of for example the above change during time?
What DocType should one use today upon creating a website?