Issue v. Argument Preservation

The record provides the raw material of an appeal; it is the closed universe in which appellate practitioners work. The Texas courts of appeal, after all, do not consider matters outside the record on appeal.[1] That’s old hat. The record is important, critically so. And, so, we are all well-acquainted with the appellate record’s preparation. The clerk and reporter—by rule and request—assemble the papers and transcripts, combine them, file them, number them, and so on.[2] Their contents turn on rule and the parties’ designations.[3] You know all that. But what about supplementing the record, say, with relevant but missing materials, after an appeal has progressed from its early administrative stages and into the merits? Can a party do that in Texas appellate courts?