:contains "text with foreign characters", correct syntax?

Is it correct to write rules in the following syntax:

if header :contains "Subject" "foreign characters, for example åäö" {
discard;
}

and store it in UTF-8


(åäö, are some swedish characters, for your information.)



Then it is a question for the sieve implementation to handle such a
script I suppose.

I tried it at CMU Sieve 2.0, but it seems not  to be implemented.

regards,
Erik Sjölund