T 6 N, R 5 E, Fifth Principal Meridian | Double Corners

That's what I would call it

That's the nomenclature I have seen and used. More modern elongated sections would have unique lot numbers for each one. 

I don't know much about Arkansas, but until 1909 there was no general statutory authority for the government to resurvey anything. Before that there were many corrective surveys, supplemental plats like this one,  and do overs, what we would today call independent resurveys. I know there were specific instances that congress authorized resurveys. Are there a lot of them in Arkansas? 

Thanks for posting. I always appreciate seeing unusual GLO plats. 

One dependent resurvey that I’m very familiar with

https://glorecords.blm.gov/results/default.aspx?searchCriteria=type=survey|st=AR|cty=|twp_nr=14|twp_dir=N|rng_nr=4|rng_dir=E