| When you want to use the following as search items | Your action is to |
|---|---|
| Synonyms, acronyms, alternate terms | Combine terms with OR |
| CAS standard abbreviations | Use ? to allow for the abbreviated and complete forms of the terms or use the SET ABBREVIATION command which instructs STN to automatically look for CAS abbreviations for any of your search terms |
| Grammatical variations | Use ? to allow for various endings, including none |
| Singular and plural word forms | Use # to allow for one or no characters at the end of a term; use multiple # if more than one character forms the plural or use the SET PLURAL command which instructs STN to automatically look for plural forms for any of your search terms |
| Spelling variations (British and American Spellings) |
Use ! to allow for any character within a term or ? to let endings vary |
| CA indexing terms | Use (S) to allow terms to be in any order, but in the same information unit |
| CAS RNs | Locate the CAS RN for the substance (REGISTRY file) and search the resulting L-number in the CAplus file |
Reproduced with the permission of CAS, a Division of the American Chemical Society, from "Tips for Searching the CAplus & REGISTRY Files." (CAS9613-0298)