 The Executive Council has the power to grant charters to new chapters and to withdraw any charter at its discretion.A two-thirds vote is required to grant a charter, and a unanimous vote is required for a withdrawal of a charter.Each chapter is chartered under the name of the institution where it is located, and will also be designated by Greek letters which will be bestowed in accordance with its date of founding in regular sequence, as ALPHA, BETA, GAMMA; and when doubling of letters shall be required, ALPHA ALPHA, ALPHA BETA, etc., are used.