Add-on to the ! feature

One day I noticed that when you !{place}, it’ll search a website. For example, !yt/!youtube {query} (such as !yt dreams j cole) will search just that on Youtube, same for example with !amazon breadboard and !pip black. However, I was wondering if it would be possible to extend this feature to allow us to add our own URLs and encoding rules. What I mean by this is:
Amazon uses it as a “k” query param, pip uses it as a “q” query param both split with +s meanwhile Google uses the ASCII encoding %20, some places use - instead, etc… Some use it as a route param instead (and some as a POST with the query in payload but less used so not a focus)
This also allows for me to modify things such as location. For example, I can use !uniqlo but it takes me to the /us/ website, I might be in a different location and therefore this doesn’t apply to me(used to be the case with Amazon too but that got changed). But more importantly, it allows me to use this shortcutting to save time searching on other website I use that aren’t as well known.

Also - what is this even called? Is there somewhere I can see the list of current options? Whoever implemented is a total genius I must say, it’s amazing.