Thanks Jongware,
I have a bit more of an insight into what's happening this morning. If I restart indesign the search works. When I try to incorporate it into my script and run it, I get no results. I then retry the grep search within indesign and the search returns no results. Other basic searches for any digit, any paragraph return, any word etc still return results. I have a couple of other find/change scripts which don't cause this crazy behaviour, so I guess I need to look at this particular one.
I tried the search you suggested, but with no results? I've also reset the preferences, but it hasn't made a difference.
I think I'm now in the wrong forum area, but does the following look ok to you?
grep {findWhat:”(?<=//d)LT”} {changeTo:”L”} {includeFootnotes:true, includeMasterPages:true, includeHiddenLayers:true, wholeWord:false} Change LT to L when preceded by a digit.
cheers.
(PS backslash replaced by a forward slash)