On Clamwin preferences, Filters tab, there is some text stating that you can specify a regular expression by using <>.
However, there are several regular expression syntaxes arround, its not standard. What syntax to use? I couldnt find it anywhere on the web.
For example, do \ need to be escaped as in \\ ? It would be useful if the dialog was a little taller with a text example of a regular expression, with a simple example, like how to exclude an entire directory from the scan.

clamwin will escape \ into \\ internally

to exclude all filesand subfolders under c:\test:
<C:\test\.*>

There are a few RegEx guides online. For RegEx syntax you may use this one:
https://docs.python.org/lib/re-syntax.html

the previous post says that clamwin internally escapes \. It appears that this is NOT the case.
I just tested it and you must escape the \ yourself to \\. So a simple example, to exclude c:\test you will need to add:
<c>

When I wrote that I couldnt find it anywhere on the web, i didnt mean a regex guide, there are lots arround. I meant that there are different syntaxes and are not standard, so just saying "use a regular expression" is not enough, it needs more detail. An example would be the escaping of \.

I think it needs to have an example on the dialog itself.

The messsage board is getting confused about double backslash so my example doesnt show right in my previous post.
The simple example should look like the example given by alch, but double-backslash everywhere there is a \