Can a spreadsheet be designed, possibly with macros, that “senses” the IDSID of the user (mine would be “ajas). A user could modify or delete ONLY those lines of the spreadsheet he/she created. And anyone can create new lines. New lines are always tagged with the IDSID of the creator (not an option, not an editable field). Any one can view everyone else’s stuff, but only edit their own. Maybe “gray out” everyone else’s data to make the distinction visible.