I'm looking into using the wildcard field type, I noticed it was part of 'x-pack' which I was not familiar with previously. After reading a bit about it, I'm quite confused. It seems to me that parts of x-pack are free and available without any activation, while other parts require a subscription, additionally some (or all?) features are available in a 30 day trial. It's unclear to me what this means for my application. I seem to be able to use the wildcard field on my development machine. Am I free to just use that without paying any sort of subscription, or is that violating the license, or is it going to stop functioning after 30 days? And if it just freely available to use, why is it part of x-pack at all? My hunch is that it was originally introduced as part of x-pack because that put it under a different license, but now everything uses the same license, so maybe things that are free don't need to part of x-pack anymore?
For some background: We are hosting elasticsearch ourselves, currently running 7.14 using the official Ubuntu packages.