[Users] Simplify Subject RegExp

[Paul]

On Sat, 14 Aug 2021 15:36:12 +0200
Johan Vromans <jvromans at squirrel.nl> wrote: 

> In the folder properties, I can specify a 'Simplify Subject RegExp'. 
> 
> Is the format for the RegExp described somewhere? I'm looking for a case
> insensitive match.

It's POSIX Extended Regular Expression syntax.
For further info, e.g. see `man 7 regex` and
http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap09.html

with regards

Paul