[Rey_a]

Claude,

Glad I was able to help.

I never had to look at organising my registration files in the way you are doing now.
I sold my Tyros 5 over 4 years ago.  At the time of my Tyros I must have had some 120 registration files in total. Today I have some 280 registration files I use. So I never really had a problem with the max of 500 files in a folder on Tyros. 
Also, I prefer loading a song manually in MobileSheets, and- as a result - have the corresponding registration file button activated automatically on my keyboard (which currently is a Genos). You seem to prefer it the other way around (to press a reg file button, and have that load the sheet in MobileSheets). Which for tyros would of course have other file naming requirements than the ones I use.

A Genos can store 2500 files in a folder (compared to the 500 of T5). So I will always be able to keep all my registration files in one folder on the keyboard. So my naming conventions are limited to starting the registration file name with a number ...
000 Song x
001 Song y
....
A leftover from the time I had a Tyros. But I still follow that naming convention. It is not required for Genos any more as Genos is able to make the link between a song in MSPro and a registration file on the keyboard based on the actual file name and full path of the registration file.
But as said, I still name my registration files that way.

Best regards

Rudy