Burrell v. State
Sometimes the State alleges evidentiary matters in its indictment which are not "necessary to be proved" under Art. 21.03.
These allegations are considered "surplusage."
In Burrell v. State, 526 S.W.2d 799 (Tex. Crim. App. 1975) the Court explained that "allegations not essential to constitute the offense, and which might be entirely omitted without affecting the charge against the defendant, and without detriment to the indictment are treated as mere surplusage, and may be entirely disregarded."
The exception to that rule is when "the unnecessary matter is descriptive of that which is legally essential to charge a crime."