So yeah... no documentation for the HBase REST API in regards to what should a filter look like...
So I installed Eclipse, got the library, and took some time to find some of the (seemingly) most useful filters you could use. I'm very green at anything regarding HBase, and I hope this will help anyone trying to get started with it.
What I discovered is that basically, attributes of the filter object follow the same naming than in the documentation. For this reason, I have made the link clickable and direct them to the HBase Class documentation attached to it; check for the instantiation argument names, and you will have your attribute list (more or less).