The term "Iaido katana" is not a specific type of sword or a distinct category of weaponry. It seems to be a combination of the terms "Iaido" and "katana," referring to a katana that is used for the practice of Iaido.

In the context of Iaido, practitioners typically use a standard katana, which is a traditional Japanese sword characterized by its curved, single-edged blade and long grip. However, it's important to note that the katana used in Iaido practice is often an unsharpened training sword called an "iaito" (as previously mentioned), which is specifically designed for safe and effective training.

An iaito replicates the weight, balance, and overall feel of a real katana but has a blunt or rounded edge to ensure safety during practice. It allows Iaido practitioners to perform the various drawing, cutting, and resheathing techniques without the risk of accidental injury.

So, to clarify, when people refer to an "Iaido katana," they are most likely referring to an iaito, which is a katana-like training sword used in Iaido practice.