Can anybody say what exactly are the requirements for Titles of Items, Categories, Menu Items, etc. to be unique?  (Actually I care about K2 and standard Joomla 1.5.)
With two of my sites, duplicate titles are almost a requirement.  In Joomla 1.0, I had a scheme to encode the date in titles, which made them ugly of course, but if I didn't external links would get screwed up when using SEF URLs.