When searching to see whether OpenJ9 supports some JVM arg, the search box at the top of the page often fails, reporting "No matching documents" even when the arg is in fact supported and documented.
A recent example is -XX:ParallelGCThread
Searching with the full value shows "No matching documents", which does not change if I remove the "-" or remove "-XX:"
But if I start with just "Parallel" in the search box (no quotes), then '-XX:ParallelGCThread' is shown as a choice, among other JVM args containing the string 'parallel'.