How can I use LINER in iBooks? Brian July 07, 2021 02:53 Updated Follow We're sorry to tell you that you can't use LINER in iBooks. LINER only supports HTML and PDF format. Related articles How to highlight PDF files? How to highlight on iOS LINER User Guide : LINER Content Recommendation [Aug 5th] Updates - Highlight even on Youtube How to hide a popup box when you're highlighting Comments 0 comments Please sign in to leave a comment.