Important features of the Deventer Systeem

October 2022

1) Coding. Pottery and glass objects are assigned a three-part designation: first, a single or two-letter code  designates the fabric, second, a three-letter code designates the use function; and third, a number designates the type of pottery. Example: r-pis-1 is a redware (r), pispot or in English a chamber pot (pis), type 1 (1), a w-pis-1 is a whiteware, pispot, type 1 and g-pis-1 is a greyware, pispot, type 1. Within the Deventer System, more than 60 fabrics have been identified, more than 200 uses and more than 5,000 types. One example of each type has been established as the base object, which is the most characteristic form of that type. Below is an example of an r-pis-1 and a w-pis-1. Note that the shape of a whiteware pispot, type 1 is different from that of a redware pispot, type 1. 

2) Catalogue. Archaeological reports that apply the Deventer System contain a catalogue of finds that are virtually archaeologically complete. In principle, the catalogue in an archaeological report contains one example of each type. With the number of recorded objects increasing, this principle is no longer strictly applied. New Deventer System types should always be included in an archaeological report catalogue and should be accompanied by a drawing and a photograph. 

3) A count list of each find complex should be included in the archaeological report. It contains the type codes and the number of pieces found in the complex. The count list thus comprises both types included in the catalogue and non-archaeologically complete objects. Traditionally, pottery and glass in the Deventer System has been counted using the Minimum Number of Vessels. This because initially only find complexes from cesspits were included. These finds are usually fairly complete. Now that the Deventer System also increasingly unlocks finds from excavation layers with a high degree of fragmentation, the use of Estimated Vessel Equivalents (EVE) has become more common. To determine EVE, a circular chart (Rim chart) is used to determine the correct percentage (or number of degrees) of the remaining rim.  

Count lists have not been included in the master database of the Deventer System up to this point. The pie chart colour scheme is a tool designed by Nina Jaspers to show the proportion of the fabrics is available at the website.  

4) Editorial check. From the start, an editorial team has monitored the quality of the published catalogues. Catalogues that were submitted were checked and new type numbers issued. This checking was almost always a labour of love and often took a long time to complete. To cope with the increasing number of catalogues, as stated in the October 2022 Newsletter, one hour will be charged for 20 catalogue blocks. Small catalogues of up to 50 blocks will be checked within two weeks. For 50+ blocks, the delivery time will be negotiated. For online checks, the editors adjust the types in the catalogue but keep a record of what has been adjusted in a Word file and provide feedback to the applicant.