You can see from the login message that the SCIsearch file includes citing articles from 1974 to the present. That means that you can forward search from articles earlier than that date, but will not find any hits prior to 1974. The file is updated weekly with approximately 14,000 new and updated records. For records since 1983, the Research Front information is included.
All information is searchable.
Stopwords are not indexed in the Basic Index, the abstract, and the title. For information on the most recent updates to the file, enter NEWS FILE at an arrow prompt. You should note, however that the AN is the SCI accession number, not the CAS accession number. The end of the record, however is different. Beginning at the RE , you find that the record contains a reference table of all of the footnotes that were included in the article.