Question: I am trying to match a string that has the form:

```
abcd:vxyz

```

That is: 4 chars followed by a colon then followed by three (or maximum) 4 chars.

I want to do case INSENSITIVE matches.

Can anyone help with the pattern?

Answer: 
```
/^[a-z]{4}:[a-z]{3,4}$/i

```

........
Your example was alphabetical, but it was unclear if your desired regex should be limited to that. If you wanted to match *any* characters in those groups:

```
/^.{4}:.{3,4}$/i

```