In October 1963, Toyota decided to standardize their reality for how they dealt with part numbers.
That was one of the smartest moves that Toyota ever made in terms of standardizing their kaizen program that Taichi Ohno developed when he was a manager at Toyotda Boshuku.
One of the most important ideas that Ohno transposed from his time at Boshuku was that you cannot change a culture by telling people that "they had to change their culture".
Ohno did it by emphasizing that all "trends" and "fashions" had to be disposed of. The only thing that remains are the truths: For Ohno, 10 digit part numbers pulled from the kanban system by the rank and file.
And that distilled down to all of the Toyota Group keiretsu companies.
All of the Toyota Group companies adopted and developed internalized part numbering systems that remained logical; they remained consistent-- They represented the best of the best of what they were doing during that time period which was building Toyota Land Cruisers.
Just putting some historical perspective to how the notions evolve. And how superficiality has to be disposed of no matter what.