HI...I have over 6,000 bookmarks, created as files within a single folder on firefox over the past 30 years, all of which were created on one macbook or three. I migrated Firefox to them (as well as a iphone or even Amazon Fire) without their being ruined..don't understand why they, and any other folder on the macbook show under head category of 'mobile bookmarks'. That seems contradictory. B/C I was concerned about the lack of support on firefox (and my mail server-another story), I noticed these files and the folder do not transfer, say, to Chrome (or icloud). What little info there is on mobile bookmarks doesn't have real workaround. I tried creating HTML or JSON folders on my desk top but those too aren't picked up by another browser like Chrome...furthermore, Firefox "export bookmarks" doesn't allow individual folders to be exported, only the whole lot (except those mobile ones!). NO one told me using sync (or even icloud for storing desktop files/folders) would mean I can never export to other browsers!