I found one topic that described this but I was hoping someone had some specific experience/guidance/rule coding for me... http://www.pathlabtalk.com/forum/index.php?/topic/2990-special-product-requirements/?hl=%2Bmeditech+%2Brule#entry18397 We use Meditech C/S 5.66 right now. I would like an assign/issue rule for our cellular products that checks if the patient's LIS history marker (e.g. Irradiated, CMV-negative) matches to the product being selected for their transfusion. We've identified the way to do this, by adding a rule to the Product dictionary under Page 5 (i think) but our IS people haven't been able to find the right syntax for the NPR code to get it to work - it keeps crashing the application. Does anyone have an example of coding that works for them that they would be willing to share? Does anyone have an alternative solution that they are using in their Meditech LIS? Thank you in advance for your help!!