Example:

Write this:

_SCREEN.Name=REPLICATE('A',254)
* PROPERTIES window report 'AAA...AAA'
? LEN(_SCREEN.Name) && why 254 ?
SCREEN.Name=REPLICATE('A',255)
* PROPERTIES window report 'AAA...AAA'
? LEN(_SCREEN.Name) && cut to 254 and no errors
..256-263 idem
SCREEN.Name=REPLICATE('A',264)
* PROPERTIES window report 'AAA...AAA'
? LEN(_SCREEN.Name) && cut to 254 and no errors

SCREEN.Name=REPLICATE('A',265)
* PROPERTIES window report none !
? LEN(_SCREEN.Name) && cut to 254 and no errors
* if you go on PROPERTIES window Name row and enter, it fire an error

This occur also on Class Designer (use ASELOBJ).

Writing direct on PROPERTIES window, you can write 255 chars, bat it is cut to 254.

my analysis:
on VFP internal C code it is written 264 instead of 254, but in an other part it is written sure 254.

Then, VFP Team don't uses C .h files like programming style,
or write bad .h file ( duplex costant for identical semantic data ).

We are not surprised ourselves if there are bug inexplicable.

Fabio