U+0130

[Simon Josefsson]

The informative tables in RFC 5892 suggests U+130 is disallowed:

0130        ; DISALLOWED  # LATIN CAPITAL LETTER I WITH DOT ABOVE

I cannot figure out why.  If I go through the 5892 table generating
logic (see steps below) I get it to be PVALID because it has
General_Category of Lu (and nothing else seems to disallow it).  Help?

/Simon

Exception(U+0130) = UNKNOWN
BackwardCompatible(U+0130) = UNKNOWN
	General_Category-Cn(U+0130) == FALSE
	Noncharacter_Code_Point(U+0130) == FALSE
Unassigned (U+0130) == FALSE
LDH (U+0130) == FALSE
JoinControl (U+0130) == FALSE
	toNFKC(U+0130) = U+0130
	toCaseFold(toNFKC(U+0130)) = U+0130
	toNFKC(toCaseFold(toNFKC(U+0130))) = U+0130
Unstable (U+0130) == FALSE
IgnorableProperties (U+0130) == FALSE
	Block(U+0130) = Latin Extended-A
	Combining Diacritical Marks for Symbols(U+0130) = FALSE
	Musical Symbols(U+0130) = FALSE
	Ancient Greek Musical Notation(U+0130) = FALSE
IgnorableBlocks (U+0130) == FALSE
OldHangulJamo (U+0130) == FALSE
	General_Category-Ll(U+0130) == FALSE
	General_Category-Lu(U+0130) == TRUE
	General_Category-Lo(U+0130) == FALSE
	General_Category-Nd(U+0130) == FALSE
	General_Category-Lm(U+0130) == FALSE
	General_Category-Mn(U+0130) == FALSE
	General_Category-Mc(U+0130) == FALSE
LetterDigits (U+0130) == TRUE
Property(U+0130) == PVALID