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yep, my point is that the txt part is redundant for twtxt

Also a .txt file could be in any format, for example those plans from John Carmak are stored now as .txt -> https://github.com/ESWAT/john-carmack-plan-archive/blob/master/by_day/johnc_plan_19960218.txt
Although being named .plan was expected for them to work, if I recall correctly -> http://www.catb.org/jargon/html/P/plan-file.html