Searchable field codes can be used to search within a specific section of a record, creating a search using indexed fields referenced in either the citation or full display (or full text, if available). EBSCO uses two-character abbreviations for field codes such as SU-Subject, AU-Author, or TI- Article_Title.
Since our database products are tailored to the content, field codes are database specific and not all fields are available for all products. To determine which codes are available for a specific database, you can access the Database Help section from the Help link in the upper right corner of a selected database, or from the Choose Databases screen by clicking More Information. The database help page lists all field codes for that database with explanations of what they mean.
When searching, to obtain optimal results, use Uppercase in the Find field only when selecting to search with field codes. If you enter characters in Uppercase that correlate to a field code (TO, AN, SU, DE etc.) EBSCOhost makes the assumption that you want to use a field code, rather than the word. Queries should therefore be entered in lowercase to ensure that two-character strings are not interpreted as field codes and deliver unexpected or limited results. A best practice to only search using uppercase when you want to invoke a field code.
See also: How can I limit my EBSCOhost search to articles with Full Text using Field Codes?