(1) Any person or entity whose interest may be substantially affected by a proceeding before the board may request status as an amicus. The request must be made by written motion, and must comply with WAC 456-09-555 and 456-09-345.

(2) The motion requesting amicus status must include:

(a) The applicant's interest, or the interest of the person or group represented by applicant, in the proceeding before the board;

(b) The applicant's familiarity with the issues in the proceeding before the board, and with the scope of the arguments presented or to be presented by the parties;

(c) The specific issues to which the brief will be directed; and

(d) The applicant's reason as to why additional argument is necessary on the issues identified.

(3) The deadline for filing an amicus brief is the same as the deadline for the filing of the brief for the party whose position the amicus supports.

(4) The board, on its own motion and with notice to the parties, may request a brief of amicus from any person or entity deemed to be substantially affected by a proceeding.