Encode For Regular Expression Filter

Very useful filter

Does anyone know what the logic is for this?

I don't see that function with a lot of other tools and if I could convert my strings to that format with some rules I would love to have that in my back pocket

I'm not sure what you want when you say that, but it looks to me like that filter converts regex's into URL-compatible strings.

If you tell me what you mean by "convert my strings to that format" by showing what your "before string" and "after string" are, I can possibly help. It's hard to tell what you mean by "I want to convert my strings."

As you can see from the greyed text at the bottom of this image, the filter you are talking about appears to convert non-alphabetic characters into \x values usable in URLs. So I've never used it.