Maps I would like to have:

• counties ✔️
• Local Electoral Areas (2015 & 2019) :heavy_check_mark:
• administrative areas ✔️
• NUTS2 regions, NUTS3 regions ✔️
• Electoral Divisions - working on it.
• small areas - Probably not possible.

Fundamental features

• easy to use format like CSV ✔️ Using geojson instead, which is really handy.
• code uploaded showing how source shapefiles were manipulated ✔️
• region names compatible with CSO/Pobal HP ✔️ (done for LEAs)
• Northern Ireland outline ✔️
• compatible projections ✔️

Nice-to-have features

• different maps are exactly nested :heavy_check_mark: (sort of)
• Shannon estuary is present in all maps. :heavy_check_mark:

Lessons learned

• geojson files work perfectly well
• sf easier to handle than sp in terms of loading, changing projection, plotting (tmap or geom_sf).
• st_union great for combining regions, negates need for separate production of maps of aggregated regions
• ms_clip great for subtracting shapes from regions (Shannon Estuary)
• EDs do not nest within LEAs

Questions arising

• Do LEAs, Small Areas and EDs nest within admin counties? - Answer: LEAs nest within admin counties.
• Are LAUs (local authority units, f.k.a. NUTS4) the same as admin counties? - Answer: No! They are Electoral Divisions!