Patent attributes
An ink annotation sharing method is carried out in a system, which includes a first terminal operable by a first user, a second terminal operable by a second user, and an ink annotation sharing system. The ink annotation includes a stroke data set indicating an annotation added to an electronic book and metadata. The metadata includes a user identifier, a book identifier, and place data indicating a place of the annotation. The method includes transmitting, by the first terminal, the ink annotation generated by an operation of the first user, to the ink annotation sharing system; identifying, by the ink annotation sharing system, the second user who is a member of a group that relates to the electronic book and that is configured by the first user based on the user and book identifier values; and supplying, by the ink annotation sharing system, the ink annotation to the second terminal.