What are the general term used for class ruling?

Terms generally used for class ruling are schemes, the entity, the principal, the applicant, the participant which  explains in detail below:
• Scheme: It is the general term ATO used to represent any arrangement, agreement, plan, proposal, course of action, action, course of conduct, understanding, undertaking or promise. 
• Entity: Entity refers to body corporate, partnership, a person, body politic and other body of persons or unincorporated association, superannuation fund or trust.
• The principal: An entity who undertakes the specified arrangement or scheme and principle will also in the participants list in the scheme.
• The applicant: Entity applies  to  class ruling instead of  principal, potential participants or participants in the plan. They may be a  tax agent acts instead of the participants or principal
• The participant: Entity within a particular class enters into arrangement of scheme which are described above.