Tex. R. Civ. P. 276
When an instruction, question, or definition is requested and the provisions of the law have been complied with and the trial judge refuses the same, the judge shall endorse thereon "Refused," and sign the same officially. If the trial judge modifies the same the judge shall endorse thereon "Modified as follows: (stating in what particular the judge has modified the same) and given, and exception allowed" and sign the same officially. Such refused or modified instruction, question, or definition, when so endorsed shall constitute a bill of exceptions, and it shall be conclusively presumed that the party asking the same presented it at the proper time, excepted to its refusal or modification, and that all the requirements of law have been observed, and such procedure shall entitle the party requesting the same to have the action of the trial judge thereon reviewed without preparing a formal bill of exceptions.
Tex. R. Civ. P. 276