When linking to external content the link address may change so that the link no longer works. It would be great if there was a routine that would scan the links in the gudebook and list the content that had the broken link. It would save the embarrasment when a customer tried to access content that was missing and also help keep the content up to date. Perhaps it could work like a broken link checker for websites e.g. https://www.brokenlinkcheck.com/