The following are known issues with this release of SICStus. See Limitations in the Current Release for more missing or incomplete features in this release.
When reading terms, SICStus Prolog currently does not verify that the input text contains valid Unicode 5.0 characters in Normal Form C. See Syntax of Tokens as Character Strings.
This is not a problem as long as the input is in the proper format but it will accept some input that may be rejected or interpreted differently in a future version of SICStus Prolog.