This field represents a condensation or compression of the way the contract refers to itself on its title page. Although there is frequent classification of petroleum contracts into three main categories - royalty/tax, production sharing and risk service agreement – the repository does not currently use a normalised taxonomy to define contractual documents in this way. In practice there are other kinds of agreement as well in the petroleum industry, and also agreements which are primarily one kind of contract can include elements of another. For example, many PSCs also include royalties. In addition, the repository contains both main Host Government Contracts but also ancillary agreements such as amendments and assignations. Classification according to any normalised system would require more time than was available. This feature may be introduced at a later date. The initial approach is non-normative, designed to provide the user with a hint to the nature of the document rather than a firm taxonomy.