At the moment, the citation processing rules are configured in such a way to only enable the generation of purchase requests if the criteria of the rule are met.
It would be useful if it was possible to also create rules which could specify that a purchase request should not be generated if the criteria are met, and to be able to set the rules in order of priority. This should work in the same way as the fulfillment unit rules so that rules are worked through from top to bottom and only the first applicable rule is used; all the rest are ignored.

Use case: for citations with digitisation, system generated tags are added as part of the DCS integration, alongside the importance tags added by lecturers. The importance tags are used to generate purchase requests if no electronic availability. Purchase requests are rejected and deleted if a digitisation is processed for a citation. The DCS integration includes the running of a daily overnight job to sync and update citations in Alma with the correct status from the DCS. As part of this, the citation is updated, which then causes the purchasing rules to generate another purchase request, which staff have to again reject and delete, causing unnecessary duplication of work.

We would like to be able to configure a rule to NOT generate a purchase request if any of the digitisation-related tags are present, and for this rule to take precedence over all other rules related to importance tags.