Do we need to search Web of Science citation indexes for systematic reviews?

Web of Science Core Collection List of Databases Varies Depending on Institutional Subscription

Before you judge, I am not sure if the plural form is citation indices or citation indexes, so if you have studied English, Help! [Thanks to Liz on Twitter quoting from “Index, A History of the” that indices are for mathematicians & economists; indexes are what you find at the back of a book].

When did WoS start to be…