In addition, each file has a basic index , which is the default index searched if you don't specify a particular index. The fields included in the basic index may vary from file to file. In most bibliographic files, it includes terms from the title, abstract and subject headings . It will display 12 terms unless you specify otherwise. By entering e again, you can see more of the list.
Searches generate answer sets which are designated with L numbers .
Like most electronic search systems, Messenger allows truncation of terms, but with much greater flexibility than most. Proximity operators allow you to specify the relationships between terms. Same as above, but terms can be in either order. This is very useful for searching abstracts or full-text files. The STN online equivalent of the basic Chemical Abstracts database is the CA file.