I would like to call your attention to three relatively new items on my ftp site, all joint with John Kennison and Bob Raphael: Local extension of maps, Isbell duality, Isbell duality for modules. To see them, simply browse to ftp.math.mcgill.ca/pub/barr/pdffiles and click on Index.html. Michael [For admin and other information see: http://www.mta.ca/~cat-dist/ ]