(1) All covered entities must register to participate in the program, following procedures adopted by the department by rule.

(2) Entities registering to participate in the program must describe any direct or indirect affiliation with other registered entities.

(3) A person responsible for greenhouse gas emissions that is not a covered entity may voluntarily participate in the program by registering as an opt-in entity. An opt-in entity must satisfy the same registration requirements as covered entities. Once registered, an opt-in entity is allowed to participate as a covered entity in auctions and must assume the same compliance obligation to transfer compliance instruments equal to their emissions at the appointed transfer dates. An opt-in entity may opt out of the program at the end of any compliance period by providing written notice to the department at least six months prior to the end of the compliance period. The opt-in entity continues to have a compliance obligation through the current compliance period. An opt-in entity is not eligible to receive allowances directly distributed under RCW 70A.65.110, 70A.65.120, or 70A.65.130.

(4) A person that is not covered by the program and is not a covered entity or opt-in entity may voluntarily participate in the program as a general market participant. General market participants must meet all applicable registration requirements specified by rule.

(5) Federally recognized tribes and federal agencies may elect to participate in the program as opt-in entities or general market participants.

(6) The department shall use a secure, online electronic tracking system to: Register entities in the state program; issue compliance instruments; track ownership of compliance instruments; enable and record compliance instrument transfers; facilitate program compliance; and support market oversight.

(7) The department must use an electronic tracking system that allows two accounts to each covered or opt-in entity:

(a) A compliance account where the compliance instruments are transferred to the department for retirement. Compliance instruments in compliance accounts may not be sold, traded, or otherwise provided to another account or person.

(b) A holding account that is used when a registered entity is interested in trading allowances. Allowances in holding accounts may be bought, sold, transferred to another registered entity, or traded. The amount of allowances a registered entity may have in its holding account is constrained by the holding limit as determined by the department by rule. Information about the contents of each holding account, including but not limited to the number of allowances in the account, must be displayed on a regularly maintained and searchable public website established and updated by the department.

(8) Registered general market participants are each allowed an account, to hold, trade, sell, or transfer allowances.

(9) The department shall maintain an account for the purpose of retiring allowances transferred by registered entities and from the voluntary renewable reserve account.

(10) The department shall maintain a public roster of all covered entities, opt-in entities, and general market participants on the department's public website.

(11) The department shall include a voluntary renewable reserve account.