Any IACS Member can submit a proposal to the IACS Bureau to initiate a Working Group (WG). WGs address scientific problems of the cryosphere that are timely and well constrained.WGs shall have explicit aims, objectives, milestones and deliverables. They should be international in composition. They shall define the instruments, for example workshops and conferences, which they will use to achieve their aims and objectives. Working Groups will normally be limited to up to four years duration. They may be renewed for up to a further four years in exceptional circumstances. Working Groups report annually to the Bureau through the appropriate IACS Head of Division. The chair, co-chairs, and all of Working Group members must be IACS members. See the Terms of Reference (ToR) for further information.