OK, I see, http://www.unicode.org/versions/Unicode5.2.0/ch03.pdf (Table 3-7 on page 93) states that the only valid 3-bytes UTF-8 sequences starting with the byte 0xED have a value for the second byte in the range 0x80 to 0x9F. 0xA0 is just beyond that range (as that would result in an encoded surrogate). Python handles all invalid sequences according to that table with the same error message. I think this issue can be closed.