How you treat numbers when you search depends on which search engine you're using.
Windows Search (the default)
If you're using Windows Search (the default), it fully recognizes numbers and currency values, regardless of whether you use or omit the thousands separator. There's nothing special you need to do.
dtSearch (formerly called Advanced Search)
With FileCenter Professional's dtSearch engine, any punctuation is treated as a word separator by the indexer, even with numbers. So the number 28.88 is treated as two distinct numbers: 28 and 88.
Further, by default dtSearch does an "any" search, meaning that it will return documents that match ANY of those terms. In other words, if you search for 28 88, your results will show documents that contain either 28 or 88.
Your best friends when you do number searches with dtSearch are quotations marks "". Quotations force an "exact phrase" search, which works great with numbers.
If you search for "28.88" (including the quotation marks) you'll get much better results. You could just as well search for "28 88" since, as we said, punctuation is ignored.
A few more number examples:
800-123-4567 – matches any document that has any of these numbers: 800 123 4567
"800-123-4567" – matches only documents that have the exact sequence of numbers 800 123 4567 (hyphens are ignored)
"-12.345" – matches only documents that have the exact sequence of numbers 12 345 (negative signs and decimals are ignored)
1,234,567 – matches any document that has 1 OR 234 OR 567
"1,234,567" – matches any document that has the exact number sequence 1 234 567 (commas are ignored)