A novel but subsequently disastrous feature designed by Bell Antwerp was used to hold the subscriber’s class of service information i.e. PBX, shared service, incoming calls barred (ICB), temporary out of service (TOS) etc. This was a capacitor store, and it held information on a thin plastic strip, into which could be inserted up to 10 little copper squares which had a capacitance of 10 pF. The thin plastic strips were then inserted into the Data Store rack, one at the position representing the directory number and another at the position representing the equipment number. This can be seen in the photograph together with some plastic strips hanging by wire. Hanging the strips by wire was a common practice for subscribers who were constantly changing their Class of Service, i.e. being made TOS. This information was then pulsed by the common control translator and appropriate action taken. In the end the problem turned out to be cable interference requiring substantial re-cabling at the rear of the rack. This system was replaced in later TXE exchanges by Dimond Rings.