Keywords may be separated by AND and/or OR statements for greater control of the search results.
For example, cat AND mouse would generate a result set that contain both words. However, for alien OR rocket, the result set returned would contain both or either words.
Exact matches can be searched for by enclosing keywords in double-quotes.
For example, "gift voucher" would generate a result set which match the exact string.
Brackets can be used for further control on the result set.
For example, rocket and (planet or alien or "moon surface").
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