Supplemental Documents

If your normal process was to generate letter size documents for the project, then I don't see why GBCI would need to have them changed to another format. Legibility and usability will be the key for any submission. I'd like to believe that the GBCI won't be printing things out if they don't have to, so the size and format of the documents probably isn't as important compared to usability of the information. If you are referring to a document that you are making solely for LEED upload purposes, then as long as it conveys the needed information it will be fine.