| Operator | Relationship of Terms | Example |
|---|---|---|
| AND | Both terms must be present in an answer |
=> S ANABOLIC AND STEROID? |
| OR | At least one term from a series must be present in an answer; enclose terms in parenteses. |
=> S (HEART OR CARDI?) |
| NOT | Eliminate terms; use with caution |
=> S PLASMA NOT BLOOD |
| (W) | Terms are adjacent and in the order entered; automatically supplied by STN if necessary when a phrase is entered |
=> S X-RAY
STN searches X (W) RAY |
| (S) | Terms are in the same information unit (title/indexing field) or the same sentence in the abstract in any order and with any number of words in between |
=> S GAS (S) CHROMATOG? |
Reproduced with the permission of CAS, a Division of the American Chemical Society, from "Tips for Searching the CAplus & REGISTRY Files." (CAS9613-0298)