Similar to what Wing said about 10 years ago.. I use the following to tidy up with a 'search and delete line' regex function in NP++
<search text>\r?\n?
In Wing's example: <search text>\xd?\xa
\x matches a hex code that corresponds to its ASCII counterpart
\xd (or \x0d) is used in Wing's example, instead of \r in my example
\xd means 'use hexadecimal d', which is 13 in decimal, and in ASCII '13' is a carriage return \r
Similarly for \xa (or \x0a), hexadecimal 'a' is 10 in decimal, which is a new line feed \n in ASCII.
See https://www.asciitable.com/ for all the ascii codes
The '?'s just make them optional
So use either of these in regex mode:
<search text>\r?\n?
or
<search text>\xd?\xa? (same thing as <search text>\x0d?\x0a?)
For example, I often strip unnecessary lines from online courses' table of contents:
Original text:
Dictionaries, Part I
checkmark circle
6m 25s
In NPP++
Regex mode ticked
Find what: checkmark circle\r?\n?
Replace with:
New text:
Dictionaries, Part I
6m 25s