17 CFR § 240.19c-3 - Governing off-board trading by members of national securities exchanges.
The rules of each national securities exchange shall provide as follows:
(a) No rule, stated policy or practice of this exchange shall prohibit or condition, or be construed to prohibit, condition or otherwise limit, directly or indirectly, the ability of any member to effect any transaction otherwise than on this exchange in any reported security listed and registered on this exchange or as to which unlisted trading privileges on this exchange have been extended (other than a put option or call option issued by the Options Clearing Corporation) which is not a covered security.
(b) For purposes of this rule,
(1) The term Act shall mean the Securities Exchange Act of 1934, as amended.
(3) The term covered security shall mean (i) Any equity security or class of equity securities which
(A) Was listed and registered on an exchange on April 26, 1979, and
(B) Remains listed and registered on at least one exchange continuously thereafter;
(ii) Any equity security or class of equity securities which
(A) Was traded on one or more exchanges on April 26, 1979, pursuant to unlisted trading privileges permitted by section 12(f)(1)(A) of the Act, and
(B) Remains traded on any such exchange pursuant to such unlisted trading privileges continuously thereafter; and
(iii) Any equity security or class of equity securities which
(A) Is issued in connection with a statutory merger, consolidation or similar plan or reorganization (including a reincorporation or change of domicile) in exchange for an equity security or class of equity securities described in paragraph (b)(3)(i) or (ii) of this rule,
(B) Is listed and registered on an exchange after April 26, 1979, and
(C) Remains listed and registered on at least one exchange continuously thereafter.
(4) The term reported security shall mean any security or class of securities for which transaction reports are collected, processed and made available pursuant to an effective transaction reporting plan.
(6) The term effective transaction reporting plan shall mean any plan approved by the Commission pursuant to § 242.601 of this chapter for collecting, processing, and making available transaction reports with respect to transactions in an equity security or class of equity securities.