title: Strange underline symbols in vim
body: <p>Could you please tell me what does the underline symbols in the picture mean (they are not there in insert mode, when I write something to that place it will get underlined) and how to get rid of them?</p>
  
  <p><img src="https://i.stack.imgur.com/QxbpQ.png" alt="enter image description here"></p>
  
  <p>thank you</p>