What storage requirement has FLOAT(24) ? Doc is ambigous

[Ulrich Knappe]

What memory requirement has FLOAT(24) ?

MySQL Ref.manual says in Chapter 10.2 Numeric Datatypes:
"A precision from 0 to 23 results in a four-byte single-precision FLOAT column. A precision from 24 to 53 results in an eight-byte double-precision DOUBLE column."
--> FLOAT(24) = 8 Bytes

However in Chapter 10.5. Data Type Storage Requirements:
"FLOAT(p) 4 bytes if 0 <= p <= 24, 8 bytes if 25 <= p <= 53"
--> FLOAT(24) = 4 Bytes

Which is one true?

Thanks for replies.