The game development package [Unity](http://unity3d.com) uses the following version numbering scheme:

```
{major}.{minor}.{patch}{type}{number}

```

With the following known types:

* **a** = alpha
* **b** = beta
* **f** = final

Some examples:

* 1.2.3a27
* 1.2.3b4
* 1.2.3f2

Is this a standard formatting for version numbers?