Often when they say "brief" it pertains to HPI - History of Present Illness
You are correct in that it is not a recognized level for overall history which would be Problem Focused, Expanded Problem Focused, Detailed or Comprehensive
If you have a full note you want to share I can help more. I'd look to see if they document review of systems at all and did they document any PFSH. If so then I'd consider "brief history" to mean "brief HPI".