Recently, we were implementing a user-support system of which Redmine was only a part. This system included other external scripts which were reading/modifying Redmine issues through its REST API. Eventually, we figured that automatic modification of the issues' tag list would also be useful for us - however, current version of the tags plugin doesn't support this. This is a suggestion to add such functionality - that is, to be able to read/write the tag list through the REST API.