Source of non-printing characters?

[DashboardNovice]

Over the years when doing a VLOOKUP, I have noticed that at times non-printing characters may appear in my Excel data. I can't remember what my data source was at these times because these cases were from a few years ago.

What are the sources of these non-printing characters? Where do they come from?

 

[pecoflyer]

Non printing characters usually come from imported text data ( carriage returns,...)
Tips for "cleaning "dirty" data" :https://www.rondebruin.nl/win/s9/win017.htm