Rule 18. Methods of Appeal

(a) The Court will entertain the following appeals:
(1) Cases under Article 67(a)(3). Cases under Article 67(a)(3), UCMJ, 10 USC § 867 (a)(3) (1989), including decisions by a Court of Criminal Appeals on appeal by the United States under Article 62, UCMJ, 10 USC § 862 (1983), may be appealed by the filing of a petition for grant of review by an appellant or by counsel on behalf of an appellant substantially in the form provided in Rule 20 (a) or (b).
(2) Cases under Article 67(a)(2). Cases under Article 67(a)(2), UCMJ, 10 USC § 867 (a)(2) (1989), including decisions by a Court of Criminal Appeals on appeal by the United States under Article 62, UCMJ, 10 USC § 862 (1983), which are forwarded by a Judge Advocate General by a certificate for review must be substantially in the form provided in Rule 22 (a).
(3) Cases under Article 67(a)(1). Cases under Article 67(a)(1), UCMJ, 10 USC § 867 (a)(1) (1989), will be forwarded by a Judge Advocate General by the filing of the record with the Court, together with the form prescribed by Rule 23 (a).
(4) Cases under Rule 4 (b)(2). Decisions by a Court of Criminal Appeals on petitions for extraordinary relief may be appealed by filing a writ appeal petition in accordance with Rules 27 (b) and 28.
(b) In addition, the Court may, in its discretion, entertain petitions for extraordinary relief including, but not limited to, writs of mandamus, writs of prohibition, writs of habeas corpus, and writs of error coram nobis. See Rules 4 (b)(1), 27 (a) and 28.