OT05315 | PRT: valuation of crude oils and products- category 1 oil introduction
From HM Revenue & Customs · Oil Taxation Manual
These are the kinds of oil which have price assessments published and widely available (this includes reports that are only commercially available by subscription or otherwise making payment to the publisher of the price report).
Generally, oil companies subscribe to recognised Price Reporting Agencies (PRAs) if they need pricing information.
Currently the Category 1 oils defined in the Oil Taxation (Market Value of Oil) Regulations 2006 [SI2006\3313] are:
Brent
Forties
Ekofisk
Statfjord
Flotta