HP Reference Information Storage System Version 1.6 User Guide revision 2 (T3559-90810, August 2007)

Word characters and separators
Word characters include all uppercase and lowercase letters, digits, and the following additional
characters:
• _(underscore)
• # (number/pound/hash sign)
• & (ampersand)
All other chara
cters are separators (excep t i n queries, wildcards ? and *, and special quer y characters
~, ", -,and!).
However, && by itself is not a word. It is a Boolean operator. When com bined with at least one more
word characte
r, && canbepartofaword. Forexample,a&&b is a word.
Query analysis and document indexing are not case-sensitive. Uppercase and lowercase letters are
treated the same.
Regular expression definition of English word characters
The following regular expression provides, in succinct form, a complete specification of English word
characters (except for treatment of && as a non-word):
[ A-Za-z0-9_#& ]+
Letters and digits in different character sets
Topics include:
•
Letters and
digits defined, page 34
•
Letters and digits in files, page 34
Letters and digits defi ned
All letters and digits are word characters. What RISS considers a letter or digit depends on the character
set encoding used. For US ASCII encoding, letters are uppercase a nd lowercase English letters (A-Z, a-z) .
For ISO 8859-1 (Latin-1) encoding, used for Western European languages, accented letters are included.
Most ideographic characters, such as those used in A sian la n guages, are also c onsidered letters.
Whatever the language and encoding used for a par ticular document ( file or email m essage), RISS maps
encoded characters to the Unicode 2.0 standard. The Unicode 2.0 standard is then used to determine if
a given character is a letter or a digit (or neither):
• A letter is any Unicode character in one of the following Unicode categories: Ll (lowercase letter),
Lu(uppercaseletter),Lt(titlecaseletter),Lm(modifier letter), or Lo (other letter).
• A digit is any Unicode character whose Unicode name contains the word DIGIT, provided it is not
in the range \u2000 (en quad = en space) through \u2FFF (ideographic description - future) .
Letters and digits in files
Although all letters and digits are word characters, their treatment in files (including email message
attachments) depends on the character encoding used. You can search for any words in email message
bodies and headers, regardless of the encoding.
You can search for words in files (including email body, header, at tachments, and indexed documents)
provided the character encoding is one the following:
34
Query expression syntax and matching