Thank you for sharing this very useful information @Hubert-Dudek 

Cool. This is a very convenient feature since most people now use the PDF format when working with text files. If anyone has ever had any issues with this format, I can say that I recently needed to merge several PDF files into one, and with the help of the online editor http://pdfguru.com/ I was able to do it quite easily and quickly. As I understand, it has quite a lot of features, plus you don’t need to download any additional apps, so it might come in handy for someone.