That doesn’t mention PL/I, so it’s the competition for amateurs. https://www.cs.vu.nl/grammarware/browsable/os-pli-v2r3/:

    Summary
    Number of keywords: 310

PL/I made life ‘easier’ by not making keywords reserved, allowing you to use variable names that match the strings used to identify keywords, though, so you didn’t have to learn them all.