Some parts of the Mueller report regarding the investigation into alleged Russian interference with the 2016 US presidential elections, some of the footnotes refer to documents with coded names/titles. Examples:
See SM-2589105 serials 144 & 495.
See SM-2589105-HACK, serial 5.
See SM-2589105-GJ, serial 649.
What do these footnotes refer to, and are these publicly-available documents?