File icon with a cross, what does it mean?

Question

A file icon shown below has a cross on the lower right corner, what does that mean?

Answer 1

You don't have read permission for that file.

Answer 2

Simple self-answering test:

• Create an empty file

  touch ~/bar
  

  

• Remove the read permissions

  chmod -r ~/bar
  

  

Answer 3

You can provide others read access to that file so that it wont display.

sudo chmod o+r <your_filename>