The delivered stopword file fultext.stp has no lines redefining the character classes; the default settings are:
AL="\u0041-\u005A\u0061-\u007A\u00E0-\u00FE"
AC="\u00C0-\u00CF"
AJ="\u0027"
DI="\u0030-\u0039"
DJ="\u002C\u002E"
This translates to:
AL contains A-Z, a-z, and all supplemental text characters.
AC contains all supplemental punctuation characters.
AJ contains \&'.
DI contains 0-9.
DJ contains \&. and \&,.
All other characters are word breaks and do not appear in the indexed terms.