the view that, at the time, the Unicode classifications of characters were considered a little soft
FYI, I asked about Unicode category stability on the Unicode list, and received the following info:
From: "Andrew C. West" <[EMAIL PROTECTED]>
According to my calculations, the number of characters which changed their General Category from one version of Unicode to the next is :
1.1.5 -> 2.0.14 = 474 (1.384%) 2.0.14 -> 2.1.2 = 1 (0.0025%) 2.1.2 -> 2.1.5 = 16 (0.0410%) 2.1.5 -> 2.1.8 = 18 (0.0462%) 2.1.8 -> 2.1.9 = 3 (0.0077%) 2.1.9 -> 3.0.0 = 85 (0.2182%) 3.0.0 -> 3.0.1 = 0 (0%) 3.0.1 -> 3.1.0 = 3 (0.0061%) 3.1.0 -> 3.2.0 = 7 (0.0074%) 3.2.0 -> 4.0.0 = 16 (0.0168%) 4.0.0 -> 4.0.1 = 1 (0.0010%) 4.0.1 -> 4.1.0 = 12 (0.0124%)
I don't know what this tells you about the stability of the UCD data though.
