There are versions of Unitrunker that allow you to Hide a talkgroup or radio ID. I don't know what version you're using, but you might try double-clicking on 65536 talkgroup, and checking "Hide" if it's there. In the version I have, you also have to check "Hide" above the history window. I don't see that in the version you are using. That seems to hide it from the history, although it's still there if you want to un-hide it, and it still appears in the activity area above.