For each product NAG maintains a list of known issues that may be present in the software available to our users. This list contains a number of important details relating to the error that enables users to establish whether their application might be susceptible to the problem. To achieve this there is a brief description of how the error might manifest itself in terms of a user application. There is also a brief description of specific parameter settings that might force the error condition together with an assessment of the severity of the error. Finally, details of any possible workarounds are given; these can be used as an interim measure until the software is corrected by NAG. Details of known deficiencies in current implementations of our numerical library based products can be accessed using the links provided.