The Unicode Consortium Discussion Forum

"The Unicode radical-stroke charts are based on the KangXi radicals. The Unicode Standard follows a number of different sources for radical-stroke classification. Where two sources are at odds as to radical or stroke count for a given character, the character is shown in both positions in the radical-stroke charts."

See this paragraph on page 405 of Chapter 12 : East Asian Scripts under Radical Stroke Indices. The emphasis is mine.

On this site you'll find that the character U+272F0 has 19 strokes by Taiwanese and 13 strokes by Chinese standards. Right here, I can see the character U+272F0 at the line = 2, column = 30, at the 7 strokes line. According to what is written above in blue, shouldn't I be able to find the same character at a new position on this chart ?

If you actually read the comments, you would see that the Taiwan stroke count is just plain wrong. There is no way to make U+272F0 a 19 stroke character. One hypothesis is that it might have been confused in the Taiwanese listing with U+27499, which is 19 strokes, and differs only in having a doubled radical.

I've read the comments and one of them, by Andrew West, sent me to one of his blogs which tells a different story. If I understood it correctly, the author literally says that the character U+272F0 is a "phantom hanzi".