Tex. R. App. P. 47.4

As amended through August 21, 2020
Rule 47.4 - Memorandum Opinions

If the issues are settled, the court should write a brief memorandum opinion no longer than necessary to advise the parties of the court's decision and the basic reasons for it. An opinion may not be designated a memorandum opinion if the author of a concurrence or dissent opposes that designation. An opinion must be designated a memorandum opinion unless it does any of the following:

(a) establishes a new rule of law, alters or modifies an existing rule, or applies an existing rule to a novel fact situation likely to recur in future cases;
(b) involves issues of constitutional law or other legal issues important to the jurisprudence of Texas;
(c) criticizes existing law; or
(d) resolves an apparent conflict of authority.

Tex. R. App. P. 47.4