The Irish horse register also incorporates the Irish sport horse stud book. The Irish horse register seems to be a combination of the ID studbook and the Irish sport horse stud book as well as other stuff. So if she's registered with the Irish sport horse stud book within the Irish horse register. Then she's an ISH. As others have stated in this thread, I was under the impression that an Irish sport horse was an ID x. Because a more sporty version of a ID was wanted. So they crossed it with TB. I thought when some one said. ISH it meant IDXTB, as I haven't come across an ISH which has no ID or TB in. ID I thought was the vital component? Educate me folks