The updated FIH Indoor Tournament Regulations come into effect from 1 January 2019.
FIH has updated the Indoor Tournament Regulations. The significant changes come in Regulation #5.2, with the additional person allowed on the team bench (the role of this person is at the discretion of the team concerned) and Regulation# 13, which has been completely redrafted to allow for a force majeure event.
More info: http://www.fih.ch/inside-fih/our-official-documents/event-resources/