From http://icu-project.org/apiref/icu4j/com/ibm/icu/text/SpoofChecker.html :
SINGLE_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are from the same script
MIXED_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are NOT from the same script
WHOLE_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are NOT from the same script BUT both of them are single-script strings
ANY_CASE: Deprecated.
SINGLE_SCRIPT: Deprecated.
INVISIBLE: Check an identifier for the presence of invisible characters, such as zero-width spaces, or character sequences that are likely not to display, such as multiple occurrences of the same non-spacing mark.
CHAR_LIMIT: Check that an identifier contains only characters from a specified set of acceptable characters.
Explanation of whole script, mixed script and single script confusables in UTS 39 section 4 : http://unicode.org/reports/tr39/#Confusable_Detection
Details from Java SpoofChecker class at http://icu-project.org/apiref/icu4j/com/ibm/icu/text/SpoofChecker.html