The notes on a drawing set are where the designer writes what can't be drawn: design standards, material grades, loads, tolerances, sequences and workmanship. They apply to every sheet they cover, and they are the part of a set most often skipped.
Drawings show shape and position. Everything else the designer needs to say goes into notes: which standard the design follows, what the materials are, what loads it carries, how it is to be built. A coordinator who reads only the drawn views is reading half the instruction.
Sheet 4 of the Benton Street Bridge (in the lesson on plans and sections) carries a note beside the girder details. In short: the girder flanges are joined to the web by two continuous shop welds made by an automatic process, flange splices are placed where stresses are no more than 75% of the full section, and at field splices the flanges are welded first, then the web. That is a sequence, a fabrication method and a design limit, none of which a 3D model of the girder would show.
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