Just to clarify: are you saying that the link I included is showing the result that you want to see in $regml()?
Yes. The website has an option to actually hide non participating group, sort of what you get without /F in mIRC (unsure it's exactly the same). When I open your link I see a non participating group for match 1.
the 's' is definitely being returned as a match
I didn't say otherwise, but 's' is match number two, not number one (and given the pattern having only one capturing group, there's a correspondance between match number and capture number), so $regml(1) should be $null and $regml(2) should be 's'
