Tags give the ability to mark specific points in history as being important
LAST_BEFORE_PROJECT_RESTRUCTURE After this tag, the directory structure, packages etc. are restructured to make place for Project3000, new textures etc.
LAST_COPY_TEX Last version to allow copying textures etc. into each lat/lon directory. Now min version FG2017.2.1
LAST_READ_FILES Last version with (partial) support for reading OSM data from files instead of database