The handwritten annotations in red ink appear to be a legend or a list of geographical features and their intended representation on the map. The text translates to:
обозначить (to designate/mark)
океаны (oceans)
моря (seas)
реки (rivers)
озера (lakes)
острова (islands)
полуострова (peninsulas)
This suggests that the map uses different symbols or shadings to represent these different types of water bodies and landforms, and the annotations are a key to understanding those representations.