For example, say you have a few links to a hair item. You then at some point rez out that hair item to edit it, then take it back into inventory. The item will have a new UUID, so all your links to that item will be broken. To fix those links, proceed as follows:
NOTE: This function is handy if you also have broken links in inventory that you wish to repair.
See this page for documentation on Firestorm 5.0.1 (52150) and earlier.